An efficient algorithm for sequencing peptides using fast atom bombardment mass spectral data.

Area of Science:

• Proteomics
• Analytical Chemistry
• Biochemistry

Background:

• Peptide sequencing is crucial for protein identification and functional studies.
• Mass spectrometry, particularly Fast Atom Bombardment (FAB) and tandem MS, provides essential data for peptide analysis.
• Existing methods may face challenges in efficiently interpreting complex fragmentation patterns.

Purpose of the Study:

• To develop and present an efficient algorithm for peptide sequencing.
• To utilize sequence ions from FAB and FAB tandem mass spectra for accurate peptide identification.
• To address the computational complexity in determining peptide sequences from mass spectrometry data.

Main Methods:

• Representing sequence ions as combinations of N- and C-terminal fragment ions.
• Mathematically re-expressing sequence ions as N-terminal residue ions based on known termini and molecular weight.
• Iteratively computing the peptide sequence using mass differences between residue ions and predicted subsequences.
• Utilizing pre-computed and tabulated amino acid residue masses based on FAB fragmentation rules.

Main Results:

• Successfully applied the algorithm to sequence decapeptyl (MW 1310), angiotensin II (MW 1045), and two unknown peptides (MW 1227 and 1485).
• Demonstrated the algorithm's efficiency in handling complex peptide sequences.
• Validated the algorithm's accuracy in reconstructing peptide sequences from mass spectrometry data.

Conclusions:

• The developed algorithm provides an efficient and accurate method for peptide sequencing.
• The algorithm effectively utilizes FAB and FAB tandem mass spectrometry data for sequence determination.
• This approach aids in the identification and characterization of peptides in complex biological samples.