조용주 (충남대학교 화학과)

조용주 (충남대학교 화학과)

Liquid chromatography-mass spectrometry (LC-MS) is one of the most commonly used analytical methods for characterizing sample mixtures. For the LC-MS analysis of proteins, proteins are commonly digested into smaller peptide fragments. The purpose of this study is to identify the most efficient digestion method for a protein sample among three different sample preparation methods such as precipitation with trichloroacetic acid, filtration using membrane filters, and C18 cartridge solid-phase extraction (SPE). These methods were used to quantitatively and systematically analyze peptides in a specific lactic acid bacteria where the samples include sample X (liquid medium), sample A (liquid medium with Lactobacillus gasseri XXA), and sample B (liquid medium with Lactobacillus gasseri XXB). The resulting peptides were analyzed using LC-MS. The largest number of peptides was identified using C18 cartridge SPE where Compound Discoverer analysis identified 49 peptides in sample X, 97 peptides in sample A, and 99 peptides in sample B.