Wolosker H, Panizzutti R, Engelender S
Departamento de Bioquímica Médica, Instituto de Ciencias Biomédicas,Universidade Federal do Rio de Janeiro, Brazil.
FEBS Lett. 1996 Sep 2;392(3):274-6. doi: 10.1016/0014-5793(96)00829-0.
The sarcoplasmic reticulum-bound creatine kinase from rabbit skeletal muscle was inhibited by the nitric oxide donor S-nitrosoglutathione (GSNO). This led to a decrease in Ca2+ uptake in sarcoplasmic reticulum vesicles when the transport was driven by ATP generated from phosphocreatine and ADP. In contrast, the Ca 2+ transport measured using 2 mM ATP as substrate was unaffected by GSNO up to 200 microM. GSNO (5-20 microM) inhibited the activity of both soluble and membrane-bound creatine kinase. Oxyhemoglobin (15-40 microM) protected creatine kinase against inactivation by GSNO. The inhibition by 10 microM GSNO was reversed by the addition of dithiothreitol (2 mM). The results indicate that nitric oxide (NO, including NO+, NO and NO-) inactivates creatine kinase in vitro by promoting nitrosylation of critical sulphydryl groups of the enzyme.
来自兔骨骼肌的肌浆网结合型肌酸激酶受到一氧化氮供体S-亚硝基谷胱甘肽（GSNO）的抑制。当转运由磷酸肌酸和ADP生成的ATP驱动时，这导致肌浆网囊泡中Ca2+摄取减少。相比之下，以2 mM ATP作为底物测量的Ca2+转运在高达200 microM的GSNO作用下不受影响。GSNO（5-20 microM）抑制可溶性和膜结合型肌酸激酶的活性。氧合血红蛋白（15-40 microM）保护肌酸激酶不被GSNO灭活。加入二硫苏糖醇（2 mM）可逆转10 microM GSNO的抑制作用。结果表明，一氧化氮（NO，包括NO+、NO和NO-）在体外通过促进该酶关键巯基的亚硝基化使肌酸激酶失活。
