Creatine kinase in serum: 1. Determination of optimum reaction conditions.
نویسندگان
چکیده
To establish optimum conditions for creatine kinase (EC 2.7.3.2) activity measurement with the creatine phosphate in equilibrium creatine reaction, we re-examined all kinetics factors relevant to an optimal and standardized enzyme assay at 30 and 25 degrees C. We determined the pH optimum in vaious buffers, considering the effect of the type and concentration of the buffer, as well as the influence of various buffer anions on the activity. The relation between activity and substrate concentration was shown and the apparent Michaelis constants of creatine kinase for creatine phosphate and ADP were evaluated. We tested the effect on creatine kinase measurement of the concentration of substrates (glucose and NADP+) in the auxillary and indicator reactions, especially the influence of the added auxiliary (hexokinase) and indicator (glucose-6-phosphate dehydrogenase) enzymes on the lag phase, at different temperatures. The NADP+ concentration proved to be the factor limiting the duration of constant reaction rate. We studied the inhibition of creatine kinase and adenylate kinase by AMP and established a convenient AMP concentration. For reactivation of creatine kinase, N-acetyl cysteine as sulfhydryl compound was introduced. Finally, we examined the relationship between activity and temperature.
منابع مشابه
Evaluation of cardiac troponin I (cTnI), electrocardiography, creatine kinase (CK) and aspartate aminotransferase (AST) in diagnosis of selenium deficiency in Markhoz goat kids breed
BACKGROUND: Cardiac Troponin I (cTnI) is known as a cardiac biomarker in determining the myocardial damage of diseases which affect the heart muscle. OBJECTIVES: This study aims to evaluate the serum cTnI concentration in Markhoz Breed goats suffering selenium (Se) deficiency and its correlation with electrocardiographic parameters, and activity of creatine kinase (CK) and aspartate aminotransf...
متن کاملNOVEL REAGENTS FOR CREATINE KINASE
The purpose of this investigation was to develop a simple colorimetric method for creatine kinase (CK). The new method is based on the reaction of creatine, formed enzymatically from creatine phosphate and ADP, with different glyoxal compounds. Hydrated glyoxals, such as para-nitrophenyl, 2-thiophene, 4- biphenyl, 4, 4' -biphenyl,α-naphthyl, β-naphthyl, para-chlorophenyl, and styryl were...
متن کاملCreatine kinase: re-examination of optimum reaction conditions.
I have re-examined optimum reaction conditions for measurement of creatine kinase (EC 2.7.3.2). The optimum pH is 6.45, and 2,2-bis(hydroxymethyl)-2,2',2''-nitrotriethanol acetate, 200 mmol/liter, is the buffer of choice. Thioglycerol, 20 mmol/liter, is superior for both in-assay reactivation and for storage stability of sera. Fluoride, 25 mmol/liter, a broad inactivator of adenylate kinase (EC...
متن کاملThe Interventional Effect of Dry Cupping Therapy and Creatine Supplementation on Lactic Acid, Lactate Dehydrogenase and Creatine Kinase in Plasma Following Wingate Anaerobic Test in Male Handball Players
Introduction: Optimum recovery can prevent the athlete's functional capacity from falling between training sessions or competitions. The aim of this study was to evaluate the effect of dry cupping therapy and creatine supplementation on lactic acid, lactate dehydrogenase and plasma creatine kinase following the Wingate anaerobic test in male handball players. Method: In this quasi-experimental...
متن کاملFluorometric measurement of creatine kinase activity.
SERUM CREATINE KINASE activity has beell measured by determining the amount of creatine liberated in the following reaction: ADI + creatine phosphate ATP + creatine. The Voges-Proskauer reactioii, production of a color by reaction of creatille with diacetyl alid -naphthol, has heeii used to measure enzymatically released creatine (1-5). The presence of a sulfhydryl compound in tile incubatioii ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Clinical chemistry
دوره 22 5 شماره
صفحات -
تاریخ انتشار 1976