Neutralizing positive charges at the surface of a protein lowers its rate of amide hydrogen exchange without altering its structure or increasing its thermostability.

ABSTRACT: This paper combines two techniques--mass spectrometry and protein charge ladders--to examine the relationship between the surface charge and hydrophobicity of a representative globular protein (bovine carbonic anhydrase II; BCA II) and its rate of amide hydrogen-deuterium (H/D) exchange. Mass spectrometric analysis indicated that the sequential acetylation of surface lysine-ε-NH3(+) groups--a type of modification that increases the net negative charge and hydrophobicity of the surface of BCA II without affecting its secondary or tertiary structure--resulted in a linear decrease in the aggregate rate of amide H/D exchange at pD 7.4, 15 °C. According to analysis with MS, the acetylation of each additional lysine generated between 1.4 and 0.9 additional hydrogens that are protected from H/D e

SUBMITTER: Shaw BF 

PROVIDER: S-EPMC3135700 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature