Date of Award
2009
Document Type
Thesis
Publication Status
Version of Record
Submission Date
October 2026
Abstract
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.
Extent
x, 92 p. : ill. (some col.)
Recommended Citation
Livingston, Paula A., "Purification and characterization of two members of the protein tyrosine phosphatase family" (2009). Electronic Theses and Dissertations 2000 - 2009. 1760.
https://digitalcommons.fau.edu/etd_general_5/1760
Identifier
FADT332911
Comments
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.|by Paula A. Livingston.