Quantitative protein stability measurement in vivo.

Published

Journal Article

The equilibrium between the native and denatured states of a protein can be key to its function and regulation. Traditionally, the folding equilibrium constant has been measured in vitro using purified protein and simple buffers. However, the biological environment of proteins can differ from these in vitro conditions in ways that could significantly perturb stability. Here, we present the first quantitative comparison between the stability of a protein in vitro and in the cytoplasm of Escherichia coli using amide hydrogen exchange detected by MALDI mass spectrometry (SUPREX). The results indicate that the thermodynamic stability of monomeric lambda repressor within the cell is the same as its stability measured in a simple buffer in vitro. However, when the E. coli are placed in a hyperosmotic environment, the in vivo stability is greatly enhanced. The in vivo SUPREX method provides a general and quantitative way to measure protein stabilities in the cell and will be useful for applications where intracellular stability information provides important biological insights.

Full Text

Duke Authors

Cited Authors

  • Ghaemmaghami, S; Oas, TG

Published Date

  • October 1, 2001

Published In

Volume / Issue

  • 8 / 10

Start / End Page

  • 879 - 882

PubMed ID

  • 11573094

Pubmed Central ID

  • 11573094

International Standard Serial Number (ISSN)

  • 1072-8368

Digital Object Identifier (DOI)

  • 10.1038/nsb1001-879

Language

  • eng