PMID: 4240May 1, 1976

Creatine kinase in serum: 1. Determination of optimum reaction conditions

Clinical Chemistry
G SzaszE Bernt

Abstract

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...Continue Reading

Related Concepts

Blood Glucose
Ampholytes
Macro-Creatine Kinase
Enzyme Activation
Glucose, (beta-D)-Isomer
Hexokinase 2
Hydrogen-Ion Concentration
Magnesium
NADP
Osmolality

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis is a rare rheumatic disease that affects children. Symptoms include joint pain, but also fevers and skin rashes. Here is the latest on this disease.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Central Pontine Myelinolysis

Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Pontocerebellar Hypoplasia

Pontocerebellar hypoplasias are a group of neurodegenerative autosomal recessive disorders with prenatal onset, atrophy or hypoplasia of the cerebellum, hypoplasia of the ventral pons, microcephaly, variable neocortical atrophy and severe mental and motor impairments. Here is the latest research on pontocerebellar hypoplasia.

Cell Atlas Along the Gut-Brain Axis

Profiling cells along the gut-brain axis at the single cell level will provide unique information for each cell type, a three-dimensional map of how cell types work together to form tissues, and insights into how changes in the map underlie health and disease of the GI system and its crosstalk with the brain. Disocver the latest research on single cell analysis of the gut-brain axis here.

Chronic Traumatic Encephalopathy

Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease that occurs in individuals that suffer repetitive brain trauma. Discover the latest research on traumatic encephalopathy here.