Electrospray droplet exposure to gaseous acids for the manipulation of protein charge state distributions.

ABSTRACT: The exposure of electrospray droplets to acid vapors can significantly affect protein charge state distributions (CSDs) derived from unbuffered solutions. Such experiments have been conducted by leaking acidic vapors into the counter-current nitrogen drying gas of an electrospray interface. On the basis of changes in protein CSDs, protein folding and unfolding phenomena are implicated in these studies. Additionally, noncovalently bound complexes are preserved, and transient intermediates are observed, such as high charge state ions of holomyoglobin. CSDs of proteins containing disulfide bonds shift slightly, if at all, with acid vapor leak-in, but when these disulfide bonds are reduced in solution, charge states higher than the number of basic sites (Lys, Arg, His, and N-terminus) are obse

SUBMITTER: Kharlamova A 

PROVIDER: S-EPMC2940272 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature