Return to search

Purification and characterization of two members of the protein tyrosine phosphatase family: dual specificity phosphatase PVP and low molecular weight phosphatase WZB

by Paula A. Livingston. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web. / Two protein tyrosine phosphatases, dual specificity phosphatase PVP and low molecular weight phosphatase WZB were purified and characterized. PVP was expressed as inclusion bodies and a suitable purification and refolding method was devised. Enzyme kinetics revealed that p-nitrophenylphosphate and (Sb(B-naphthyl phosphate were substrates with KM of 4.0mM and 8.1mM respectively. PVP showed no reactivity towards phosphoserine. Kinetic characterization of WZB showed that only pnitrophenylphosphate was a substrate with no affinity for Ç-naphthyl phosphate and phosphoserine. Optimal conditions for activity with PNPP were found at a pH of 5 with a KM of 1.1mM, kcat of 35.4s-1 and kcat/KM of 32.2s-1mM-1. Inhibition studies showed that phosphate, fluoride, and molybdate were competitive inhibitors with Ki of 3.2mM, 71.7mM, and 50.4(So(BM respectively and hydrogen peroxide abolished activity. Active site mutants of WZB Cys9Ser and Asp115Asn showed no activity.

Identiferoai:union.ndltd.org:fau.edu/oai:fau.digital.flvc.org:fau_3750
ContributorsLivingston, Paula A., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
PublisherFlorida Atlantic University
Source SetsFlorida Atlantic University
LanguageEnglish
Detected LanguageEnglish
TypeText, Electronic Thesis or Dissertation
Formatx, 92 p. : ill. (some col.), electronic
Rightshttp://rightsstatements.org/vocab/InC/1.0/

Page generated in 0.0016 seconds