[HTML][HTML] Roles of superoxide radical anion in signal transduction mediated by reversible regulation of protein-tyrosine phosphatase 1B
WC Barrett, JP DeGnore, YF Keng, ZY Zhang… - Journal of Biological …, 1999 - ASBMB
Growth factors induce intracellular production of reactive oxygen species in non-phagocytic
cells and elevation of their phosphorylated protein tyrosine level. The latter can be achieved
by activating protein-tyrosine kinases and/or inactivating protein-tyrosine phosphatases
(PTPs). A highly abundant PTP, PTP-1B, is known to be inactivated by oxidation of its
catalytic site Cys-215. We show that O· ̄ 2 is kinetically more efficient and chemically more
specific oxidant than H 2 O 2 for inactivating PTP-1B. The second-order rate constant for the …
cells and elevation of their phosphorylated protein tyrosine level. The latter can be achieved
by activating protein-tyrosine kinases and/or inactivating protein-tyrosine phosphatases
(PTPs). A highly abundant PTP, PTP-1B, is known to be inactivated by oxidation of its
catalytic site Cys-215. We show that O· ̄ 2 is kinetically more efficient and chemically more
specific oxidant than H 2 O 2 for inactivating PTP-1B. The second-order rate constant for the …