Peptide identification method based on subset error rate estimation

Abstract

The invention relates to a peptide identification method based on subset error rate estimation. The peptide identification method comprises the following steps: 1, analyzing a peptide sample to be identified by a mass spectrometer to generate a tandem mass spectrum; 2, searching a target-bait protein database containing a target peptide sequence in the tandem mass spectrum, and sorting obtained peptide identification results according to scores from high to low; 3, setting a score threshold value x, and estimating the error rate FDRk(x) of a type k peptide identification subset, the score of which is higher than x, by a transferring FDR (False Discovery Rate) method; 4, finding the minimum value of x by adjusting the score threshold value x to enable the estimated FDRk(x) to be less than a given error rate control level alpha, so that the obtained type k peptide identification result with the score higher than x serves as an acceptable reliable identification result. The peptide identification method provided by the invention estimates the subset error rate through the transferring FDR method and obtains the reliable peptide identification result through the subset error rate, thus having high identification accuracy.

Description

technical field [0001] The invention belongs to the technical field of protein analysis, in particular to a peptide identification method based on subset error rate estimation. Background technique [0002] It is well known that the genetic information of most organisms is stored in DNA. DNA generates messenger RNA through the process of transcription, and messenger RNA generates protein through the process of translation, thus realizing the transmission of genetic information from DNA to RNA and then to protein. This process is also known as the central dogma of life. In the process of protein translation from RNA, the chain molecules formed by connecting 20 kinds of amino acids in sequence with peptide bonds are called peptides, and the peptides whose molecular weight reaches a certain level are called proteins. After most proteins are translated, some functional groups will be added to certain amino acids in the protein (such as adding acetyl at the N-terminal of the pro...

AI Technical Summary

Problems solved by technology

In extreme cases, if a subset contains only one identification, then the target-decoy library approach cannot be used to estimate the FDR of this subset at all, thus preventing reliable identification of peptides

Images