학술논문
Toward the bilayer proteome, electrospray ionization-mass spectrometry of large, intact transmembrane proteins
Document Type
Academic Journal
Author
Source
Proceedings of the National Academy of Sciences of the United States. Sept 14, 1999, Vol. 96 Issue 19, p10695, 4 p.
Subject
Language
ISSN
0027-8424
Abstract
Genes encoding membrane proteins comprise a substantial proportion of genomes sequenced to date, but ability to perform structural studies on this portion of the proteome is limited. Electrospray ionization-MS (ESI-MS) of an intact protein generates a profile defining the native covalent state of the gene product and its heterogeneity. Here we apply ESI-MS technology with accuracy exceeding 0.01% to a hydrophobic membrane protein with 12-transmembrane [Alpha]-helices, the full-length lactose permease from Escherichia coli. Furthermore, ESI-MS is used to titrate reactive thiols with N-ethylmaleimide. Treatment of the native protein solubilized in detergent micelles reveals only two reactive thiols, and both are protected by a substrate analog.