Abstract: In proteomic research, it is often necessary to screen a large number of polypeptides for the presence of stable structure. Described herein are methods (referred to as MALDI MS-HX and SUPREX) for measuring the stability of proteins in a rapid, high-throughput fashion. The method employs hydrogen exchange to estimate the stability of quantities of unpurified protein extracts, using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. A method of quantitatively determining the stability of a test protein under native conditions is disclosed.

Abstract: The invention provides a novel protein that, when expressed in a host cell, increases cellular biomass and cellular protein production and secretion. The invention also provides a polynucleotide encoding the novel protein, and methods for using the polynucleotide and encoded protein to increase cellular biomass and cellular protein production and secretion. Also provided is a genetically altered mutant cell strain with enhanced production and secretion of cellular and heterologous proteins.