Competitive binding affinity studies of gas phase noncovalent complexes between staphylococcal nuclease and its inhibitors by ESI-FTMS

by Gong, Weihong; Fritsch, Ingrid; Wilkins, Charles L.

The effect of amino acid mutation of staphylococcal nuclease (SNase) on its binding affinity and preferential binding of SNase to different inhibitors were discussed. To test how amino acid mutation affects the binding affinity of SNase to inhibitor pdTp, competitive studies between wild type and mutant Gali, or wild type and mutant D21K were performed in 2.5 mM ammonium acetate/methanol. The results show that Ca2+ is not present in the complexes between SNase and inhibitors in the gas phase. The competitive study of binding wild type SNase to different inhibitors demonstrated that wild type SNase preferentially binds to pdTp over dAMP and dTMP.

Proceedings - 50th ASMS Conference on Mass Spectrometry and Allied Topics