PMID: 45380Mar 1, 1979

Creatine kinase in serum: 6. Inhibition by endogenous polyvalent cations, and effect of chelators on the activity and stability of some assay components

Clinical Chemistry
G SzaszW Gruber


We studied the effects of some chelators on creatine kinase activity. Creatine kinase is competitively inhibited by endogenous polyvalent cations (e.g., calcium, Ki = 4.5 mmol/L); this can be reversed by adding chelators to the reagent, resulting in a mean increase in activity of 1.14-fold at 25 degrees C and 1.18-fold at 30 and 37 degrees C. Adding chelators, 5 and 10 mmol/L, to serum stored at 37, 30, 25, 4, and -20 degrees C increased isoenzyme stability in some cases, but under certain conditions decreased it, especially at higher chelator concentrations, and more so for EGTA than for EDTA. Blood sampling into tubes prepared with chelators and storage of plasma has no advantage over serum stored in the presence of chelators. The most striking effect of chelators is their protective effect on thiols in the creatine kinase reagent. In the presence of EDTA, 2 mmol/L, the reagent is stable for at least a day at 25 degrees C or a week at 4 degrees C. The poor stability of glucose-6-phosphate dehydrogenase, which is nearly independent of chelators, is the limiting factor for reagent containing EDTA. Bis-Tris, a buffer recently recommended for assay of creatine kinase activity, is a weak chelator. Imidazole acetate buffer combined...Continue Reading

Related Concepts

Calcium [EPC]
Imidazole acetate
Collection of Blood Specimen for Laboratory Procedure
Macro-Creatine Kinase
Chelator (genus)
Chelating Agents
Sulfhydryl Compounds
Egtazic Acid

Trending Feeds


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.

Synapse Loss as Therapeutic Target in MS

As we age, the number of synapses present in the human brain starts to decline, but in neurodegenerative diseases this occurs at an accelerated rate. In MS, it has been shown that there is a reduction in synaptic density, which presents a potential target for treatment. Here is the latest research on synapse loss as a therapeutic target in MS.

Artificial Intelligence in Cardiac Imaging

Artificial intelligence (ai) techniques are increasingly applied to cardiovascular (cv) medicine in cardiac imaging analysis. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

Social Learning

Social learning involves learning new behaviors through observation, imitation and modeling. Follow this feed to stay up to date on the latest research.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Single Cell Chromatin Profiling

Techniques like ATAC-seq and CUT&Tag have the potential to allow single cell profiling of chromatin accessibility, histones, and TFs. This will provide novel insight into cellular heterogeneity and cell states. Discover the latest research on single cell chromatin profiling here.

Genetic Screens in iPSC-derived Brain Cells

Genetic screening is a critical tool that can be employed to define and understand gene function and interaction. This feed focuses on genetic screens conducted using induced pluripotent stem cell (iPSC)-derived brain cells.