Protection of a single-cysteine redox switch from oxidative destruction: On the functional role of sulfenyl amide formation in the redox-regulated enzyme PTP1B.
Model reactions offer a chemical mechanism by which formation of a sulfenyl amide residue at the active site of the redox-regulated protein tyrosine phosphatase PTP1B protects the cysteine redox switch in this enzyme against irreversible oxidative destruction. The results suggest that 'overoxidation' of the sulfenyl amide redox switch to the sulfinyl amide in proteins is a chemically reversible event, because the sulfinyl amide can be easily returned to the native cysteine thiol residue via reactions with cellular thiols.
Sivaramakrishnan
Santhosh
S
Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA.
Cummings
Andrea H
AH
Gates
Kent S
KS
D000577:Amides / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D010084:Oxidation-Reduction; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000737:chemistry* / Q000378:metabolism; D013434:Sulfenic Acids / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry
D000577:Amides; D013434:Sulfenic Acids; D013438:Sulfhydryl Compounds; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D003545:Cysteine