Timed mass spectrometry study of sulbactam inactivation of SHV-1 and Ser130Gly beta-lactamase

ANYL 89

DL Sulton, d.sulton@csuohio.edu1, CR Bethel2, AM Hujer2, MS Helfand2, T Gootz3, VE Anderson4, RA Bonomo2, and LM Ng1. (1) Department of Chemistry, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, (2) Louis Stokes Veterans Affairs Medical Center, (3) Pfizer Global Research, Groton, CT, (4) Department of Biochemistry and Pharmacology, Case Western Reserve University, Clevland, YT
SHV-1 beta-lactamase is common class-A beta-lactamase that is susceptible to inhibition by clavulanate and by tazobactam but resistant to inhibition by sulbactam. Ser130Gly beta-lactamase is a laboratory generated variant of SHV-1 beta-lactamase which has come to be a valuable model in studying inhibitor resistance in wild-type SHV-1 beta-lactamase and the role that Ser130 plays in inhibitor resistance. Mass spectrometric time studies were done for sulbactam inhibition of SHV-1 wild-type and Ser130Gly variant beta-lactamases. As a result, multiple inhibition intermediates were found: delta -18, delta +53, delta +70, delta +88, delta +116, delta +156, delta +231, and delta +249 Da. The positive mass changes are reminiscent of previous studies for clavulanate and tazobactam. However, the delta -18 Da which was significant for SHV-1 and predominant for Ser130Gly suggests that the net loss of a water molecule and an important contribution by Ser130 in this loss.
 

General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006