title: Calculation of the isotope cluster for polypeptides by probability grouping.
abstract: This paper presents a novel theoretical basis for accurately calculating the isotope cluster of polypeptides. In contrast to previous approaches to this problem, which consider exhaustive or near exhaustive combinations of isotopic species, the program, Neutron Cluster, groups probabilities to yield highly accurate information without elucidating any fine structure within a nominal mass unit. This is a fundamental difference from any previously described algorithm for calculating the isotope cluster. As a result of this difference, the accurate isotope clusters for high molecular weight polypeptides can be calculated rapidly without any pruning. When applied to isotope enriched polypeptides, the algorithm introduces "grouping error", which is described, quantified, and avoided by using probability partitioning.
authors.affiliation: Section on Metabolism and Mass Spectrometry, National Institutes of Child Health and Human Development, National Institutes of Health, Baltimore, Maryland 21287, USA. Molson8@jhmi.edu
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Olson
authors.forename: Alfred L
authors.initials: AL
authors.lastname: Yergey
mesh_terms: D000465:Algorithms; D000818:Animals; D016000:Cluster Analysis; D003198:Computer Simulation; D056445:Cytoplasmic Dyneins; D004398:Dyneins / Q000737:chemistry; D006801:Humans; D007554:Isotopes; D009502:Neutrons; D010455:Peptides / Q000737:chemistry*; D011336:Probability
chemical_list: C511240:DYNC1H1 protein, human; D007554:Isotopes; D010455:Peptides; D056445:Cytoplasmic Dyneins; D004398:Dyneins