Effects of acrylamide on creatine kinase from rabbit muscle.
The mechanism of inhibition of creatine kinase (CK) by acrylamide (Acr) has been examined (in vitro). Within the concentration range of 0 to 1 M, Acr markedly inhibited CK and depleted the protein thiols. Both inactivation and thiol depletion were time- and Acr concentration-dependent. Addition of dithiothreitol (DTT) did not reactivate CK inactivated by Acr. However, CK with 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) pre-blocked thiols can be reactivated by DTT after incubation with Acr. The transition-state analogue also had a significant protective effect on CK against Acr inhibition. We conclude that thiol alkylation is a critical event in inactivation of CK by Acr. Furthermore, Acr binding to CK changed its surface charge, which may be the same effect for the toxicity of Acr towards other proteins.
Meng
F G
FG
Department of Biological Sciences and Biotechnology, School of Life Science and Engineering, Tsinghua University, 100084, Beijing, People's Republic of China.
Zhou
H W
HW
Zhou
H M
HM
D020106:Acrylamide / Q000494:pharmacology*; D000818:Animals; D003402:Creatine Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D052283:Creatine Kinase, MM Form; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D007700:Kinetics; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000201:enzymology*; D011487:Protein Conformation / Q000187:drug effects; D011817:Rabbits; D055672:Static Electricity; D013438:Sulfhydryl Compounds / Q000378:metabolism
D007527:Isoenzymes; D013438:Sulfhydryl Compounds; D020106:Acrylamide; D004228:Dithionitrobenzoic Acid; D003402:Creatine Kinase; D052283:Creatine Kinase, MM Form