Amino Acid Sequence Analysis of Peptides and Proteinswith Modified Amino Acid Using PPSQ™-50A Isocratic System

Introduction

Protein identification with a mass spectrometer (MS) and search engine utilizing genomic databases has now become the main stream in analysis of proteins. Although the proteins in the genomic databases are registered as precursor proteins, the expressed proteins in living cells are modified after translation and have various functions. However, since there are differences in the theoretical mass number of the precursor protein and the mature protein modified after translation, the score and reliability of search results obtained by the MS analysis and search engine is sometimes low. Moreover, identification of amino acid sequences by MS without using databases is both quite complex and difficult. On the other hand, a protein sequencer using the conventional Edman degradation method obtains highly reliable sequencing results, and amino acid sequences can be identified easily even in case the database is inadequate. This article introduces an example of amino acid sequence analysis of a sample containing a modified amino acid by using the PPSQ-50A isocratic system.

August 27, 2019 GMT