RBKS Human

Ribokinase is a carbohydrate kinase enzyme that plays a crucial role in the metabolism of ribose, a five-carbon sugar. This enzyme catalyzes the phosphorylation of ribose to ribose-5-phosphate, a key intermediate in the pentose phosphate pathway. The human recombinant form of ribokinase is produced through recombinant DNA technology, allowing for the study and utilization of this enzyme in various research and therapeutic applications.

The gene responsible for ribokinase in human cells was identified through comparative studies with the ribokinase from Escherichia coli. Researchers used BLAST searches to find a human protein with significant similarity to the bacterial ribokinase . The cDNA for this human protein was expressed in E. coli, and the recombinant protein was found to efficiently phosphorylate ribose to ribose-5-phosphate using ATP, confirming its identity as ribokinase .

Ribokinase belongs to the PfkB family of carbohydrate kinases, which includes enzymes such as adenosine kinase, inosine-guanosine kinase, fructokinase, and phosphofructokinase . Despite the low sequence identity among PfkB family members, they exhibit remarkably high structural similarity. The catalytic activity of ribokinase is dependent on the presence of inorganic phosphate, similar to other kinases in this family .

The enzyme specifically phosphorylates ribose and shows very little to no activity towards other sugars such as D-arabinose, D-xylose, D-fructose, and D-galactose . This specificity is crucial for its role in ribose metabolism.

Ribokinase plays a vital role in the pentose phosphate pathway, which is essential for the production of nucleotides and nucleic acids. Ribose-5-phosphate, the product of the ribokinase-catalyzed reaction, is a precursor for the synthesis of nucleotides, which are the building blocks of DNA and RNA .

Exogenous ribose has been shown to have beneficial effects in various studies. It enhances cardiac and muscular performance and accelerates the repletion of ATP in myocardial and endothelial cells . Ribose supplementation has also been reported to improve neurological symptoms in patients with adenylosuccinase deficiency .

The human recombinant form of ribokinase is used in research to study its structure, function, and role in metabolism. It is also utilized in therapeutic applications, particularly in conditions where ribose metabolism is impaired. The production of human recombinant ribokinase through recombinant DNA technology allows for the large-scale production of this enzyme, facilitating its use in various scientific and medical fields.