SMILES2PEPTIDE / app.py
yinuozhang's picture
bug fixing
5cfae69
import os
import gradio as gr
import gradio.blocks
from gradio.blocks import Blocks
original_get_api_info = Blocks.get_api_info
def safe_get_api_info(self):
try:
return original_get_api_info(self)
except Exception as e:
print("⚠️ Failed to generate API schema:", e)
return {}
import re
import pandas as pd
from io import StringIO
import rdkit
from rdkit import Chem
from rdkit.Chem import AllChem, Draw
import numpy as np
from PIL import Image, ImageDraw, ImageFont
import matplotlib.pyplot as plt
import matplotlib.patches as patches
from io import BytesIO
import tempfile
from rdkit import Chem
class PeptideAnalyzer:
def __init__(self):
self.bond_patterns = [
#(r'OC\(=O\)', 'ester'), # Ester bond
(r'N\(C\)C\(=O\)', 'n_methyl'), # N-methylated peptide bond
(r'N[0-9]C\(=O\)', 'proline'), # Proline peptide bond
(r'NC\(=O\)', 'peptide'), # Standard peptide bond
(r'C\(=O\)N\(C\)', 'n_methyl_reverse'), # Reverse N-methylated
(r'C\(=O\)N[12]?', 'peptide_reverse') # Reverse peptide bond
]
self.complex_residue_patterns = [
# Kpg - Lys(palmitoyl-Glu-OtBu)
(r'\[C[@]H\]\(CCCNC\(=O\)CCC\[C@@H\]\(NC\(=O\)CCCCCCCCCCCCCCCC\)C\(=O\)OC\(C\)\(C\)C\)', 'Kpg'),
(r'CCCCCCCCCCCCCCCCC\(=O\)N\[C@H\]\(CCCC\(=O\)NCCC\[C@@H\]', 'Kpg'),
(r'\[C[@]?H\]\(CSC\(c\d+ccccc\d+\)\(c\d+ccccc\d+\)c\d+ccc\(OC\)cc\d+\)', 'Cmt'),
(r'CSC\(c.*?c.*?OC\)', 'Cmt'), # Core structure of Cys-Mmt group
(r'COc.*?ccc\(C\(SC', 'Cmt'), # Start of Cmt in cyclic peptides
(r'c2ccccc2\)c2ccccc2\)cc', 'Cmt'), # End of Cmt in cyclic peptides
# Glu(OAll)
(r'C=CCOC\(=O\)CC\[C@@H\]', 'Eal'),
#(r'COc\d+ccc\(C\(SC\[C@@H\]\d+.*?\)\(c\d+ccccc\d+\)c\d+ccccc\d+\)cc\d+', 'Cmt-cyclic'),
# Dtg - Asp(OtBu)-(Dmb)Gly
(r'CN\(Cc\d+ccc\(OC\)cc\d+OC\)C\(=O\)\[C@H\]\(CC\(=O\)OC\(C\)\(C\)C\)', 'Dtg'),
(r'C\(=O\)N\(CC\d+=C\(C=C\(C=C\d+\)OC\)OC\)CC\(=O\)', 'Dtg'),
(r'N\[C@@H\]\(CC\(=O\)OC\(C\)\(C\)C\)C\(=O\)N\(CC\d+=C\(C=C\(C=C\d+\)OC\)OC\)CC\(=O\)', 'Dtg'),
]
# Three to one letter code mapping
self.three_to_one = {
'Ala': 'A', 'Cys': 'C', 'Asp': 'D', 'Glu': 'E',
'Phe': 'F', 'Gly': 'G', 'His': 'H', 'Ile': 'I',
'Lys': 'K', 'Leu': 'L', 'Met': 'M', 'Asn': 'N',
'Pro': 'P', 'Gln': 'Q', 'Arg': 'R', 'Ser': 'S',
'Thr': 'T', 'Val': 'V', 'Trp': 'W', 'Tyr': 'Y',
'ala': 'a', 'cys': 'c', 'asp': 'd', 'glu': 'e',
'phe': 'f', 'gly': 'g', 'his': 'h', 'ile': 'i',
'lys': 'k', 'leu': 'l', 'met': 'm', 'asn': 'n',
'pro': 'p', 'gln': 'q', 'arg': 'r', 'ser': 's',
'thr': 't', 'val': 'v', 'trp': 'w', 'tyr': 'y', 'Cmt-cyclic': 'Ĉ',
'Aib': 'Ŷ', 'Dtg': 'Ĝ', 'Cmt': 'Ĉ', 'Eal': 'Ė', 'Nml': "Ŀ", 'Nma': 'Ṃ',
'Kpg': 'Ƙ', 'Tpb': 'Ṯ', 'Cyl': 'Ċ', 'Nle': 'Ł', 'Hph': 'Ĥ', 'Cys-Cys': 'CC', 'cys-cys': 'cc',
}
def preprocess_complex_residues(self, smiles):
complex_positions = []
for pattern, residue_type in self.complex_residue_patterns:
for match in re.finditer(pattern, smiles):
# Only add if this position doesn't overlap with existing matches
if not any(pos['start'] <= match.start() < pos['end'] or
pos['start'] < match.end() <= pos['end'] for pos in complex_positions):
complex_positions.append({
'start': match.start(),
'end': match.end(),
'type': residue_type,
'pattern': match.group()
})
# Sort by position (to handle potential overlapping matches)
complex_positions.sort(key=lambda x: x['start'])
if not complex_positions:
return smiles, []
# Build a new SMILES string, protecting complex residues
preprocessed_smiles = smiles
offset = 0 # Track offset from replacements
protected_residues = []
for pos in complex_positions:
start = pos['start'] + offset
end = pos['end'] + offset
complex_part = preprocessed_smiles[start:end]
if not ('[C@H]' in complex_part or '[C@@H]' in complex_part):
continue
placeholder = f"COMPLEX_RESIDUE_{len(protected_residues)}"
preprocessed_smiles = preprocessed_smiles[:start] + placeholder + preprocessed_smiles[end:]
offset += len(placeholder) - (end - start)
protected_residues.append({
'placeholder': placeholder,
'type': pos['type'],
'content': complex_part
})
#print(f"Protected {pos['type']}: {complex_part[:20]}... as {placeholder}")
return preprocessed_smiles, protected_residues
def is_peptide(self, smiles):
"""Check if the SMILES represents a peptide structure"""
mol = Chem.MolFromSmiles(smiles)
if mol is None:
return False
# Look for peptide bonds: NC(=O) pattern
peptide_bond_pattern = Chem.MolFromSmarts('[NH][C](=O)')
if mol.HasSubstructMatch(peptide_bond_pattern):
return True
# Look for N-methylated peptide bonds: N(C)C(=O) pattern
n_methyl_pattern = Chem.MolFromSmarts('[N;H0;$(NC)](C)[C](=O)')
if mol.HasSubstructMatch(n_methyl_pattern):
return True
return False
def is_cyclic(self, smiles):
"""Improved cyclic peptide detection"""
# Check for C-terminal carboxyl
if smiles.endswith('C(=O)O'):
return False, [], []
# Find all numbers used in ring closures
ring_numbers = re.findall(r'(?:^|[^c])[0-9](?=[A-Z@\(\)])', smiles)
# Find aromatic ring numbers
aromatic_matches = re.findall(r'c[0-9](?:ccccc|c\[nH\]c)[0-9]', smiles)
aromatic_cycles = []
for match in aromatic_matches:
numbers = re.findall(r'[0-9]', match)
aromatic_cycles.extend(numbers)
# Numbers that aren't part of aromatic rings are peptide cycles
peptide_cycles = [n for n in ring_numbers if n not in aromatic_cycles]
is_cyclic = len(peptide_cycles) > 0 and not smiles.endswith('C(=O)O')
return is_cyclic, peptide_cycles, aromatic_cycles
def split_on_bonds(self, smiles, protected_residues=None):
"""Split SMILES into segments based on peptide bonds, with improved handling of protected residues"""
positions = []
used = set()
# First, handle protected complex residues if any
if protected_residues:
for residue in protected_residues:
match = re.search(residue['placeholder'], smiles)
if match:
positions.append({
'start': match.start(),
'end': match.end(),
'type': 'complex',
'pattern': residue['placeholder'],
'residue_type': residue['type'],
'content': residue['content']
})
used.update(range(match.start(), match.end()))
# Find all peptide bonds
bond_positions = []
# Find Gly pattern first
gly_pattern = r'NCC\(=O\)'
for match in re.finditer(gly_pattern, smiles):
if not any(p in range(match.start(), match.end()) for p in used):
bond_positions.append({
'start': match.start(),
'end': match.end(),
'type': 'gly',
'pattern': match.group()
})
used.update(range(match.start(), match.end()))
for pattern, bond_type in self.bond_patterns:
for match in re.finditer(pattern, smiles):
if not any(p in range(match.start(), match.end()) for p in used):
bond_positions.append({
'start': match.start(),
'end': match.end(),
'type': bond_type,
'pattern': match.group()
})
used.update(range(match.start(), match.end()))
bond_positions.sort(key=lambda x: x['start'])
# Combine complex residue positions and bond positions
all_positions = positions + bond_positions
all_positions.sort(key=lambda x: x['start'])
# Create segments
segments = []
if all_positions and all_positions[0]['start'] > 0:
segments.append({
'content': smiles[0:all_positions[0]['start']],
'bond_after': all_positions[0]['pattern'] if all_positions[0]['type'] != 'complex' else None,
'complex_after': all_positions[0]['pattern'] if all_positions[0]['type'] == 'complex' else None
})
for i in range(len(all_positions)-1):
current = all_positions[i]
next_pos = all_positions[i+1]
if current['type'] == 'complex':
segments.append({
'content': current['content'],
'bond_before': all_positions[i-1]['pattern'] if i > 0 and all_positions[i-1]['type'] != 'complex' else None,
'bond_after': next_pos['pattern'] if next_pos['type'] != 'complex' else None,
'complex_type': current['residue_type']
})
elif current['type'] == 'gly':
segments.append({
'content': 'NCC(=O)',
'bond_before': all_positions[i-1]['pattern'] if i > 0 and all_positions[i-1]['type'] != 'complex' else None,
'bond_after': next_pos['pattern'] if next_pos['type'] != 'complex' else None
})
else:
# Only create segment if there's content between this bond and next position
content = smiles[current['end']:next_pos['start']]
if content and next_pos['type'] != 'complex':
segments.append({
'content': content,
'bond_before': current['pattern'],
'bond_after': next_pos['pattern'] if next_pos['type'] != 'complex' else None
})
if all_positions and all_positions[-1]['end'] < len(smiles):
if all_positions[-1]['type'] == 'complex':
segments.append({
'content': all_positions[-1]['content'],
'bond_before': all_positions[-2]['pattern'] if len(all_positions) > 1 and all_positions[-2]['type'] != 'complex' else None,
'complex_type': all_positions[-1]['residue_type']
})
else:
segments.append({
'content': smiles[all_positions[-1]['end']:],
'bond_before': all_positions[-1]['pattern']
})
return segments
def clean_terminal_carboxyl(self, segment):
"""Remove C-terminal carboxyl only if it's the true terminus"""
content = segment['content']
# Only clean if:
# 1. Contains C(=O)O
# 2. No bond_after exists (meaning it's the last segment)
# 3. C(=O)O is at the end of the content
if 'C(=O)O' in content and not segment.get('bond_after'):
print('recognized?')
# Remove C(=O)O pattern regardless of position
cleaned = re.sub(r'\(C\(=O\)O\)', '', content)
# Remove any leftover empty parentheses
cleaned = re.sub(r'\(\)', '', cleaned)
print(cleaned)
return cleaned
return content
def identify_residue(self, segment):
"""Identify residue with Pro reconstruction"""
# Only clean terminal carboxyl if this is the last segment
if 'complex_type' in segment:
return segment['complex_type'], []
content = self.clean_terminal_carboxyl(segment)
mods = self.get_modifications(segment)
if content.startswith('COc1ccc(C(SC[C@@H]'):
print("DIRECT MATCH: Found Cmt at beginning")
return 'Cmt', mods
if '[C@@H]3CCCN3C2=O)(c2ccccc2)c2ccccc2)cc' in content:
print("DIRECT MATCH: Found Pro at end")
return 'Pro', mods
# Eal - Glu(OAll)
if 'CCC(=O)OCC=C' in content or 'CC(=O)OCC=C' in content or 'C=CCOC(=O)CC' in content:
return 'Eal', mods
# Proline (P) - flexible ring numbers
if any([
# Check for any ring number in bond patterns
(segment.get('bond_after', '').startswith(f'N{n}C(=O)') and 'CCC' in content and
any(f'[C@@H]{n}' in content or f'[C@H]{n}' in content for n in '123456789'))
for n in '123456789'
]) or any([(segment.get('bond_before', '').startswith(f'C(=O)N{n}') and 'CCC' in content and
any(f'CCC{n}' for n in '123456789'))
for n in '123456789'
]) or any([
# Check ending patterns with any ring number
(f'CCCN{n}' in content and content.endswith('=O') and
any(f'[C@@H]{n}' in content or f'[C@H]{n}' in content for n in '123456789'))
for n in '123456789'
]) or any([
# Handle CCC[C@H]n patterns
(content == f'CCC[C@H]{n}' and segment.get('bond_before', '').startswith(f'C(=O)N{n}')) or
(content == f'CCC[C@@H]{n}' and segment.get('bond_before', '').startswith(f'C(=O)N{n}')) or
# N-terminal Pro with any ring number
(f'N{n}CCC[C@H]{n}' in content) or
(f'N{n}CCC[C@@H]{n}' in content)
for n in '123456789'
]):
return 'Pro', mods
# D-Proline (p)
if ('N1[C@H](CCC1)' in content):
return 'pro', mods
# Tryptophan (W)
if re.search(r'c[0-9]c\[nH\]c[0-9]ccccc[0-9][0-9]', content) and \
'c[nH]c' in content.replace(' ', ''):
if '[C@H](CC' in content: # D-form
return 'trp', mods
return 'Trp', mods
# Lysine (K) - both patterns
if '[C@@H](CCCCN)' in content or '[C@H](CCCCN)' in content:
if '[C@H](CCCCN)' in content: # D-form
return 'lys', mods
return 'Lys', mods
# Arginine (R) - both patterns
if '[C@@H](CCCNC(=N)N)' in content or '[C@H](CCCNC(=N)N)' in content:
if '[C@H](CCCNC(=N)N)' in content: # D-form
return 'arg', mods
return 'Arg', mods
if content == 'C' and segment.get('bond_before') and segment.get('bond_after'):
# If it's surrounded by peptide bonds, it's almost certainly Gly
if ('C(=O)N' in segment['bond_before'] or 'NC(=O)' in segment['bond_before'] or 'N(C)C(=O)' in segment['bond_before']) and \
('NC(=O)' in segment['bond_after'] or 'C(=O)N' in segment['bond_after'] or 'N(C)C(=O)' in segment['bond_after']):
return 'Gly', mods
# Leucine patterns (L/l)
if 'CC(C)C[C@H]' in content or 'CC(C)C[C@@H]' in content or '[C@@H](CC(C)C)' in content or '[C@H](CC(C)C)' in content or (('N[C@H](CCC(C)C)' in content or 'N[C@@H](CCC(C)C)' in content) and segment.get('bond_before') is None):
if '[C@H](CC(C)C)' in content or 'CC(C)C[C@H]' in content: # D-form
return 'leu', mods
return 'Leu', mods
# Threonine patterns (T/t)
if '[C@@H]([C@@H](C)O)' in content or '[C@H]([C@H](C)O)' in content or '[C@@H]([C@H](C)O)' in content or '[C@H]([C@@H](C)O)' in content:
# Check both stereochemistry patterns
if '[C@H]([C@@H](C)O)' in content: # D-form
return 'thr', mods
return 'Thr', mods
if re.search(r'\[C@H\]\(CCc\d+ccccc\d+\)', content) or re.search(r'\[C@@H\]\(CCc\d+ccccc\d+\)', content):
return 'Hph', mods
# Phenylalanine patterns (F/f)
if re.search(r'\[C@H\]\(Cc\d+ccccc\d+\)', content) or re.search(r'\[C@@H\]\(Cc\d+ccccc\d+\)', content):
if re.search(r'\[C@H\]\(Cc\d+ccccc\d+\)', content): # D-form
return 'phe', mods
return 'Phe', mods
if ('CC(C)[C@@H]' in content or 'CC(C)[C@H]' in content or
'[C@H](C(C)C)' in content or '[C@@H](C(C)C)' in content or
'C(C)C[C@H]' in content or 'C(C)C[C@@H]' in content):
# Make sure it's not leucine
if not any(p in content for p in ['CC(C)C[C@H]', 'CC(C)C[C@@H]', 'CCC(=O)']):
if '[C@H]' in content and not '[C@@H]' in content: # D-form
return 'val', mods
return 'Val', mods
# Isoleucine patterns (I/i)
if any([
'CC[C@@H](C)' in content, '[C@@H](C)CC' in content,
'[C@@H](CC)C' in content,
'C(C)C[C@@H]' in content and 'CC(C)C' not in content
]):
if '[C@H]([C@@H](CC)C)' in content or '[C@H](CC)C' in content: # D-form
return 'ile', mods
elif '[C@H](C)CC' in content or '[C@H](CC)C' in content or 'CC[C@H](C)' in content:
return 'ile', mods
elif 'C(C)C[C@H]' in content and 'CC(C)C' not in content:
return 'ile', mods
return 'Ile', mods
# Alanine patterns (A/a)
if ('[C@H](C)' in content or '[C@@H](C)' in content):
if not any(p in content for p in ['C(C)C', 'COC', 'CN(', 'C(C)O', 'CC[C@H]', 'CC[C@@H]']):
if '[C@H](C)' in content: # D-form
return 'ala', mods
return 'Ala', mods
# Tyrosine patterns (Y/y)
if re.search(r'Cc[0-9]ccc\(O\)cc[0-9]', content):
if '[C@H](Cc1ccc(O)cc1)' in content: # D-form
return 'tyr', mods
return 'Tyr', mods
# Serine patterns (S/s)
if '[C@H](CO)' in content or '[C@@H](CO)' in content:
if not ('C(C)O' in content or 'COC' in content):
if '[C@H](CO)' in content: # D-form
return 'ser', mods
return 'Ser', mods
if 'CSSC' in content:
if re.search(r'\[C@@H\].*CSSC.*\[C@@H\]', content) or re.search(r'\[C@H\].*CSSC.*\[C@H\]', content):
if '[C@H]' in content and not '[C@@H]' in content: # D-form
return 'cys-cys', mods
return 'Cys-Cys', mods
if '[C@@H](N)CSSC' in content or '[C@H](N)CSSC' in content:
if '[C@H](N)CSSC' in content: # D-form
return 'cys-cys', mods
return 'Cys-Cys', mods
if 'CSSC[C@@H](C(=O)O)' in content or 'CSSC[C@H](C(=O)O)' in content:
if 'CSSC[C@H](C(=O)O)' in content: # D-form
return 'cys-cys', mods
return 'Cys-Cys', mods
# Cysteine patterns (C/c)
if '[C@H](CS)' in content or '[C@@H](CS)' in content:
if '[C@H](CS)' in content: # D-form
return 'cys', mods
return 'Cys', mods
# Methionine patterns (M/m)
if ('CCSC' in content) or ("CSCC" in content):
if '[C@H](CCSC)' in content: # D-form
return 'met', mods
elif '[C@H]' in content:
return 'met', mods
return 'Met', mods
# Glutamine patterns (Q/q)
if (content == '[C@@H](CC' or content == '[C@H](CC' and segment.get('bond_before')=='C(=O)N' and segment.get('bond_after')=='C(=O)N') or ('CCC(=O)N' in content) or ('CCC(N)=O' in content):
if '[C@H](CCC(=O)N)' in content: # D-form
return 'gln', mods
return 'Gln', mods
# Asparagine patterns (N/n)
if (content == '[C@@H](C' or content == '[C@H](C' and segment.get('bond_before')=='C(=O)N' and segment.get('bond_after')=='C(=O)N') or ('CC(=O)N' in content) or ('CCN(=O)' in content) or ('CC(N)=O' in content):
if '[C@H](CC(=O)N)' in content: # D-form
return 'asn', mods
return 'Asn', mods
# Glutamic acid patterns (E/e)
if ('CCC(=O)O' in content):
if '[C@H](CCC(=O)O)' in content: # D-form
return 'glu', mods
return 'Glu', mods
# Aspartic acid patterns (D/d)
if ('CC(=O)O' in content):
if '[C@H](CC(=O)O)' in content: # D-form
return 'asp', mods
return 'Asp', mods
if re.search(r'Cc\d+c\[nH\]cn\d+', content) or re.search(r'Cc\d+cnc\[nH\]\d+', content):
if '[C@H]' in content: # D-form
return 'his', mods
return 'His', mods
if 'C2(CCCC2)' in content or 'C1(CCCC1)' in content or re.search(r'C\d+\(CCCC\d+\)', content):
return 'Cyl', mods
if ('N[C@@H](CCCC)' in content or '[C@@H](CCCC)' in content or 'CCCC[C@@H]' in content or
'N[C@H](CCCC)' in content or '[C@H](CCCC)' in content) and 'CC(C)' not in content:
return 'Nle', mods
# Aib - alpha-aminoisobutyric acid (2-aminoisobutyric acid)
if 'C(C)(C)(N)' in content or 'C(C)(C)' in content or 'C(C)(C)' in content and ('C(=O)N' in segment['bond_before'] or 'NC(=O)' in segment['bond_before'] or 'N(C)C(=O)' in segment['bond_before']) and \
('NC(=O)' in segment['bond_after'] or 'C(=O)N' in segment['bond_after'] or 'N(C)C(=O)' in segment['bond_after']):
return 'Aib', mods
# Dtg - Asp(OtBu)-(Dmb)Gly
if 'CC(=O)OC(C)(C)C' in content and 'CC1=C(C=C(C=C1)OC)OC' in content:
return 'Dtg', mods
# Kpg - Lys(palmitoyl-Glu-OtBu)
if 'CCCNC(=O)' in content and 'CCCCCCCCCCCC' in content:
return 'Kpg', mods
# Tpb - Thr(PO(OBzl)OH)
if re.search(r'\[C[@]?H\]\(C\)OP\(=O\)\(O\)', content) or 'OP(=O)(O)OCC' in content:
return 'Tpb', mods
return None, mods
def get_modifications(self, segment):
"""Get modifications based on bond types and segment content - fixed to avoid duplicates"""
mods = []
# Check for N-methylation in any form, but only add it once
# Check both bonds and segment content for N-methylation patterns
if ((segment.get('bond_after') and
('N(C)' in segment['bond_after'] or segment['bond_after'].startswith('C(=O)N(C)'))) or
('N(C)C(=O)' in segment['content'] or 'N(C)C1=O' in segment['content']) or
(segment['content'].endswith('N(C)C(=O)') or segment['content'].endswith('N(C)C1=O'))):
mods.append('N-Me')
# Check for O-linked modifications
#if segment.get('bond_after') and 'OC(=O)' in segment['bond_after']:
#mods.append('O-linked')
return mods
def analyze_structure(self, smiles):
"""Main analysis function with preprocessing for complex residues"""
print("\nAnalyzing structure:", smiles)
# Pre-process to identify complex residues first
preprocessed_smiles, protected_residues = self.preprocess_complex_residues(smiles)
if protected_residues:
print(f"Identified {len(protected_residues)} complex residues during pre-processing")
for i, residue in enumerate(protected_residues):
print(f"Complex residue {i+1}: {residue['type']}")
# Check if it's cyclic
is_cyclic, peptide_cycles, aromatic_cycles = self.is_cyclic(smiles)
segments = self.split_on_bonds(preprocessed_smiles, protected_residues)
print("\nSegment Analysis:")
sequence = []
for i, segment in enumerate(segments):
print(f"\nSegment {i}:")
print(f"Content: {segment.get('content', 'None')}")
print(f"Bond before: {segment.get('bond_before', 'None')}")
print(f"Bond after: {segment.get('bond_after', 'None')}")
residue, mods = self.identify_residue(segment)
if residue:
if mods:
sequence.append(f"{residue}({','.join(mods)})")
else:
sequence.append(residue)
print(f"Identified as: {residue}")
print(f"Modifications: {mods}")
else:
print(f"Warning: Could not identify residue in segment: {segment.get('content', 'None')}")
three_letter = '-'.join(sequence)
one_letter = ''.join(self.three_to_one.get(aa.split('(')[0], 'X') for aa in sequence)
if is_cyclic:
three_letter = f"cyclo({three_letter})"
one_letter = f"cyclo({one_letter})"
print(f"\nFinal sequence: {three_letter}")
print(f"One-letter code: {one_letter}")
print(f"Is cyclic: {is_cyclic}")
print(f"Peptide cycles: {peptide_cycles}")
print(f"Aromatic cycles: {aromatic_cycles}")
return {
'three_letter': three_letter,
'one_letter': one_letter,
'is_cyclic': is_cyclic,
'residues': sequence
}
def annotate_cyclic_structure(mol, sequence):
"""Create structure visualization"""
AllChem.Compute2DCoords(mol)
drawer = Draw.rdMolDraw2D.MolDraw2DCairo(2000, 2000)
# Draw molecule first
drawer.drawOptions().addAtomIndices = False
drawer.DrawMolecule(mol)
drawer.FinishDrawing()
# Convert to PIL Image
img = Image.open(BytesIO(drawer.GetDrawingText()))
draw = ImageDraw.Draw(img)
try:
small_font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 60)
except OSError:
try:
small_font = ImageFont.truetype("arial.ttf", 60)
except OSError:
print("Warning: TrueType fonts not available, using default font")
small_font = ImageFont.load_default()
# Header
seq_text = f"Sequence: {sequence}"
bbox = draw.textbbox((1000, 100), seq_text, font=small_font)
padding = 10
draw.rectangle([bbox[0]-padding, bbox[1]-padding,
bbox[2]+padding, bbox[3]+padding],
fill='white', outline='white')
draw.text((1000, 100), seq_text,
font=small_font, fill='black', anchor="mm")
return img
def create_enhanced_linear_viz(sequence, smiles):
""""Linear visualization"""
analyzer = PeptideAnalyzer()
fig = plt.figure(figsize=(15, 10))
gs = fig.add_gridspec(2, 1, height_ratios=[1, 2])
ax_struct = fig.add_subplot(gs[0])
ax_detail = fig.add_subplot(gs[1])
if sequence.startswith('cyclo('):
residues = sequence[6:-1].split('-')
else:
residues = sequence.split('-')
segments = analyzer.split_on_bonds(smiles)
print(f"Number of residues: {len(residues)}")
print(f"Number of segments: {len(segments)}")
ax_struct.set_xlim(0, 10)
ax_struct.set_ylim(0, 2)
num_residues = len(residues)
spacing = 9.0 / (num_residues - 1) if num_residues > 1 else 9.0
y_pos = 1.5
for i in range(num_residues):
x_pos = 0.5 + i * spacing
rect = patches.Rectangle((x_pos-0.3, y_pos-0.2), 0.6, 0.4,
facecolor='lightblue', edgecolor='black')
ax_struct.add_patch(rect)
if i < num_residues - 1:
segment = segments[i] if i < len(segments) else None
if segment:
bond_type = 'ester' if 'O-linked' in segment.get('bond_after', '') else 'peptide'
is_n_methylated = 'N-Me' in segment.get('bond_after', '')
bond_color = 'red' if bond_type == 'ester' else 'black'
linestyle = '--' if bond_type == 'ester' else '-'
ax_struct.plot([x_pos+0.3, x_pos+spacing-0.3], [y_pos, y_pos],
color=bond_color, linestyle=linestyle, linewidth=2)
mid_x = x_pos + spacing/2
bond_label = f"{bond_type}"
if is_n_methylated:
bond_label += "\n(N-Me)"
ax_struct.text(mid_x, y_pos+0.1, bond_label,
ha='center', va='bottom', fontsize=10,
color=bond_color)
ax_struct.text(x_pos, y_pos-0.5, residues[i],
ha='center', va='top', fontsize=14)
ax_detail.set_ylim(0, len(segments)+1)
ax_detail.set_xlim(0, 1)
segment_y = len(segments)
for i, segment in enumerate(segments):
y = segment_y - i
# Check if this is a bond or residue
residue, mods = analyzer.identify_residue(segment)
if residue:
text = f"Residue {i+1}: {residue}"
if mods:
text += f" ({', '.join(mods)})"
color = 'blue'
else:
# Must be a bond
text = f"Bond {i}: "
if 'O-linked' in segment.get('bond_after', ''):
text += "ester"
elif 'N-Me' in segment.get('bond_after', ''):
text += "peptide (N-methylated)"
else:
text += "peptide"
color = 'red'
ax_detail.text(0.05, y, text, fontsize=12, color=color)
ax_detail.text(0.5, y, f"SMILES: {segment.get('content', '')}", fontsize=10, color='gray')
# If cyclic, add connection indicator
if sequence.startswith('cyclo('):
ax_struct.annotate('', xy=(9.5, y_pos), xytext=(0.5, y_pos),
arrowprops=dict(arrowstyle='<->', color='red', lw=2))
ax_struct.text(5, y_pos+0.3, 'Cyclic Connection',
ha='center', color='red', fontsize=14)
ax_struct.set_title("Peptide Structure Overview", pad=20)
ax_detail.set_title("Segment Analysis Breakdown", pad=20)
for ax in [ax_struct, ax_detail]:
ax.set_xticks([])
ax.set_yticks([])
ax.axis('off')
plt.tight_layout()
return fig
class PeptideStructureGenerator:
"""Generate 3D structures of peptides using different embedding methods"""
@staticmethod
def prepare_molecule(smiles):
"""Prepare molecule with proper hydrogen handling"""
mol = Chem.MolFromSmiles(smiles, sanitize=False)
if mol is None:
raise ValueError("Failed to create molecule from SMILES")
for atom in mol.GetAtoms():
atom.UpdatePropertyCache(strict=False)
# Sanitize with reduced requirements
Chem.SanitizeMol(mol,
sanitizeOps=Chem.SANITIZE_FINDRADICALS|
Chem.SANITIZE_KEKULIZE|
Chem.SANITIZE_SETAROMATICITY|
Chem.SANITIZE_SETCONJUGATION|
Chem.SANITIZE_SETHYBRIDIZATION|
Chem.SANITIZE_CLEANUPCHIRALITY)
mol = Chem.AddHs(mol)
return mol
@staticmethod
def get_etkdg_params(attempt=0):
"""Get ETKDG parameters"""
params = AllChem.ETKDGv3()
params.randomSeed = -1
params.maxIterations = 200
params.numThreads = 4 # Reduced for web interface
params.useBasicKnowledge = True
params.enforceChirality = True
params.useExpTorsionAnglePrefs = True
params.useSmallRingTorsions = True
params.useMacrocycleTorsions = True
params.ETversion = 2
params.pruneRmsThresh = -1
params.embedRmsThresh = 0.5
if attempt > 10:
params.bondLength = 1.5 + (attempt - 10) * 0.02
params.useExpTorsionAnglePrefs = False
return params
def generate_structure_etkdg(self, smiles, max_attempts=20):
"""Generate 3D structure using ETKDG without UFF optimization"""
success = False
mol = None
for attempt in range(max_attempts):
try:
mol = self.prepare_molecule(smiles)
params = self.get_etkdg_params(attempt)
if AllChem.EmbedMolecule(mol, params) == 0:
success = True
break
except Exception as e:
continue
if not success:
raise ValueError("Failed to generate structure with ETKDG")
return mol
def generate_structure_uff(self, smiles, max_attempts=20):
"""Generate 3D structure using ETKDG followed by UFF optimization"""
best_mol = None
lowest_energy = float('inf')
for attempt in range(max_attempts):
try:
test_mol = self.prepare_molecule(smiles)
params = self.get_etkdg_params(attempt)
if AllChem.EmbedMolecule(test_mol, params) == 0:
res = AllChem.UFFOptimizeMolecule(test_mol, maxIters=2000,
vdwThresh=10.0, confId=0,
ignoreInterfragInteractions=True)
if res == 0:
ff = AllChem.UFFGetMoleculeForceField(test_mol)
if ff:
current_energy = ff.CalcEnergy()
if current_energy < lowest_energy:
lowest_energy = current_energy
best_mol = Chem.Mol(test_mol)
except Exception:
continue
if best_mol is None:
raise ValueError("Failed to generate optimized structure")
return best_mol
@staticmethod
def mol_to_sdf_bytes(mol):
"""Convert RDKit molecule to SDF file bytes"""
sio = StringIO()
writer = Chem.SDWriter(sio)
writer.write(mol)
writer.close()
return sio.getvalue().encode('utf-8')
def process_input(
smiles_input=None,
file_obj=None,
show_linear=False,
show_segment_details=False,
generate_3d=False,
use_uff=False
):
"""Process input and create visualizations using PeptideAnalyzer"""
analyzer = PeptideAnalyzer()
temp_dir = tempfile.mkdtemp() if generate_3d else None
structure_files = []
# Handle direct SMILES input
if smiles_input:
smiles = smiles_input.strip()
if not analyzer.is_peptide(smiles):
return "Error: Input SMILES does not appear to be a peptide structure.", None, None, []
try:
mol = Chem.MolFromSmiles(smiles)
if mol is None:
return "Error: Invalid SMILES notation.", None, None, []
if generate_3d:
generator = PeptideStructureGenerator()
try:
# Generate ETKDG structure
mol_etkdg = generator.generate_structure_etkdg(smiles)
etkdg_path = os.path.join(temp_dir, "structure_etkdg.sdf")
writer = Chem.SDWriter(etkdg_path)
writer.write(mol_etkdg)
writer.close()
structure_files.append(etkdg_path)
# Generate UFF structure if requested
if use_uff:
mol_uff = generator.generate_structure_uff(smiles)
uff_path = os.path.join(temp_dir, "structure_uff.sdf")
writer = Chem.SDWriter(uff_path)
writer.write(mol_uff)
writer.close()
structure_files.append(uff_path)
except Exception as e:
return f"Error generating 3D structures: {str(e)}", None, None, []
segments = analyzer.split_on_bonds(smiles)
sequence_parts = []
output_text = ""
# Only include segment analysis in output if requested
if show_segment_details:
output_text += "Segment Analysis:\n"
for i, segment in enumerate(segments):
output_text += f"\nSegment {i}:\n"
output_text += f"Content: {segment['content']}\n"
output_text += f"Bond before: {segment.get('bond_before', 'None')}\n"
output_text += f"Bond after: {segment.get('bond_after', 'None')}\n"
residue, mods = analyzer.identify_residue(segment)
if residue:
if mods:
sequence_parts.append(f"{residue}({','.join(mods)})")
else:
sequence_parts.append(residue)
output_text += f"Identified as: {residue}\n"
output_text += f"Modifications: {mods}\n"
else:
output_text += f"Warning: Could not identify residue in segment: {segment['content']}\n"
output_text += "\n"
else:
for segment in segments:
residue, mods = analyzer.identify_residue(segment)
if residue:
if mods:
sequence_parts.append(f"{residue}({','.join(mods)})")
else:
sequence_parts.append(residue)
is_cyclic, peptide_cycles, aromatic_cycles = analyzer.is_cyclic(smiles)
three_letter = '-'.join(sequence_parts)
one_letter = ''.join(analyzer.three_to_one.get(aa.split('(')[0], 'X') for aa in sequence_parts)
if is_cyclic:
three_letter = f"cyclo({three_letter})"
one_letter = f"cyclo({one_letter})"
img_cyclic = annotate_cyclic_structure(mol, three_letter)
# Create linear representation if requested
img_linear = None
if show_linear:
fig_linear = create_enhanced_linear_viz(three_letter, smiles)
buf = BytesIO()
fig_linear.savefig(buf, format='png', bbox_inches='tight', dpi=300)
buf.seek(0)
img_linear = Image.open(buf)
plt.close(fig_linear)
summary = "Summary:\n"
summary += f"Sequence: {three_letter}\n"
summary += f"One-letter code: {one_letter}\n"
summary += f"Is Cyclic: {'Yes' if is_cyclic else 'No'}\n"
#if is_cyclic:
#summary += f"Peptide Cycles: {', '.join(peptide_cycles)}\n"
#summary += f"Aromatic Cycles: {', '.join(aromatic_cycles)}\n"
if structure_files:
summary += "\n3D Structures Generated:\n"
for filepath in structure_files:
summary += f"- {os.path.basename(filepath)}\n"
return summary + output_text, img_cyclic, img_linear, structure_files if structure_files else []
except Exception as e:
return f"Error processing SMILES: {str(e)}", None, None, []
# Handle file input
if file_obj is not None:
try:
if hasattr(file_obj, 'name'):
with open(file_obj.name, 'r') as f:
content = f.read()
else:
content = file_obj.decode('utf-8') if isinstance(file_obj, bytes) else str(file_obj)
output_text = ""
for line in content.splitlines():
smiles = line.strip()
if not smiles:
continue
if not analyzer.is_peptide(smiles):
output_text += f"Skipping non-peptide SMILES: {smiles}\n"
continue
try:
# Process the structure
result = analyzer.analyze_structure(smiles)
output_text += f"\nSummary for SMILES: {smiles}\n"
output_text += f"Sequence: {result['three_letter']}\n"
output_text += f"One-letter code: {result['one_letter']}\n"
output_text += f"Is Cyclic: {'Yes' if result['is_cyclic'] else 'No'}\n"
output_text += "-" * 50 + "\n"
except Exception as e:
output_text += f"Error processing SMILES: {smiles} - {str(e)}\n"
output_text += "-" * 50 + "\n"
return output_text, None, None, []
except Exception as e:
return f"Error processing file: {str(e)}", None, None, []
return (
output_text or "No analysis done.",
img_cyclic if 'img_cyclic' in locals() else None,
img_linear if 'img_linear' in locals() else None,
structure_files if structure_files else []
)
iface = gr.Interface(
fn=process_input,
inputs=[
gr.Textbox(
label="Enter SMILES string",
placeholder="Enter SMILES notation of peptide...",
lines=2
),
gr.File(
label="Or upload a text file with SMILES",
file_types=[".txt"]
),
gr.Checkbox(
label="Show linear representation",
value=False
),
gr.Checkbox(
label="Show show segmentation details",
value=False
),
gr.Checkbox(
label="Generate 3D structure (sdf file format)",
value=False
),
gr.Checkbox(
label="Use UFF optimization (may take long)",
value=False
)
],
outputs=[
gr.Textbox(
label="Analysis Results",
lines=10
),
gr.Image(
label="2D Structure with Annotations",
type="pil"
),
gr.Image(
label="Linear Representation",
type="pil"
),
gr.File(
label="3D Structure Files",
file_count="multiple"
)
],
title="Peptide Structure Analyzer and Visualizer",
description="""
Analyze and visualize peptide structures from SMILES notation:
1. Validates if the input is a peptide structure
2. Determines if the peptide is cyclic
3. Parses the amino acid sequence
4. Creates 2D structure visualization with residue annotations
5. Optional linear representation
6. Optional 3D structure generation (ETKDG and UFF methods)
Input: Either enter a SMILES string directly or upload a text file containing SMILES strings
Example SMILES strings (copy and paste):
```
CC(C)C[C@@H]1NC(=O)[C@@H](CC(C)C)N(C)C(=O)[C@@H](C)N(C)C(=O)[C@H](Cc2ccccc2)NC(=O)[C@H](CC(C)C)N(C)C(=O)[C@H]2CCCN2C1=O
```
```
C(C)C[C@@H]1NC(=O)[C@@H]2CCCN2C(=O)[C@@H](CC(C)C)NC(=O)[C@@H](CC(C)C)N(C)C(=O)[C@H](C)NC(=O)[C@H](Cc2ccccc2)NC1=O
```
```
CC(C)C[C@H]1C(=O)N(C)[C@@H](Cc2ccccc2)C(=O)NCC(=O)N[C@H](C(=O)N2CCCCC2)CC(=O)N(C)CC(=O)N[C@@H]([C@@H](C)O)C(=O)N(C)[C@@H](C)C(=O)N[C@@H](COC(C)(C)C)C(=O)N(C)[C@@H](Cc2ccccc2)C(=O)N1C
```
""",
flagging_mode="never"
)
if __name__ == "__main__":
Blocks.get_api_info = safe_get_api_info
iface.launch(share=True)