July 29, 2015, 1:04 a.m. by Rosalind Team
In “Compute the Number of Peptides of Given Total Mass”, we first encountered the problem of reconstructing a cyclic peptide from its theoretical spectrum; this problem is called the Cyclopeptide Sequencing Problem and is given below. It is solved by the following algorithm.
CYCLOPEPTIDESEQUENCING(Spectrum)
Peptides ← a set containing only the empty peptide
while Peptides is nonempty
Peptides ← Expand(Peptides)
for each peptide Peptide in Peptides
if Mass(Peptide) = ParentMass(Spectrum)
if Cyclospectrum(Peptide) = Spectrum
output Peptide
remove Peptide from Peptides
else if Peptide is not consistent with Spectrum
remove Peptide from Peptides
Given an ideal experimental spectrum, find a cyclic peptide whose theoretical spectrum matches the experimental spectrum.
Given: A collection of (possibly repeated) integers Spectrum corresponding to an ideal experimental spectrum.
Return: Every amino acid string Peptide such that Cyclospectrum(Peptide) = Spectrum (if such a string exists).
0 113 128 186 241 299 314 427
186-128-113 186-113-128 128-186-113 128-113-186 113-186-128 113-128-186
