Pyridoxal-5'-phosphate (vitamin B(6) ) is an essential cofactor for many important enzymatic reactions such as transamination and decarboxylation. African trypanosomes are unable to synthesise vitamin B(6) de novo and rely on uptake of B(6) vitamers such as pyridoxal and pyridoxamine from their hosts, which are subsequently phosphorylated by pyridoxal kinase (PdxK). A conditional null mutant of...

The nuclear fraction of rat hepatoma-derived HTC cells contained approximately 8% of the total cellular pyridoxal 5'-phosphate. HTC cells were able to metabolize [3H]pyridoxine to coenzymatically active pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate. As HTC cells did not have any demonstrable pyridoxine-5'-phosphate oxidase activity, the conversion of pyridoxine to pyridoxal 5'-phosphate ...

Vitamin B6 functions as a coenzyme in >140 enzymatic reactions involved in the metabolism of amino acids, carbohydrates, neurotransmitters, and lipids. It comprises a group of three related 3-hydroxy-2-methyl-pyrimidine derivatives: pyridoxine (PN), pyridoxal (PL), pyridoxamine (PM) and their phosphorylated derivatives [pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP)], In the f...

context advanced glycation end-products (ages) are signaling proteins associated to several vascular and neurological complications in diabetic and non-diabetic patients. ages proved to be a marker of negative outcome in both diabetes management and surgical procedures in these patients. the reported role of ages prompted the development of pharmacological inhibitors of their effects, giving ri...

We show that epd (gapB) mutants lacking an erythrose 4-phosphate (E4P) dehydrogenase are impaired for growth on some media and contain less pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP) than their epd+ parent. In contrast to a previous report, we found that gapA epd double mutants lacking the glyceraldehyde 3-phosphate and E4P dehydrogenases are auxotrophic for pyridoxine. Th...

1. The capacity ofvarious amino acids to convert the pyridoxal form ofaspartate aminotransferase into the pyridoxamine form has been investigated. 2. Glutamate has the highest converting capacity; aspartate, cx-aminopimelate, oc-aminoadipate and other amino acids follow. 3. The converting capacity of the various amino acids assayed is connected with their structural features. 4. A possible role...

This work was presented in part at the 8th International Congress of Haematology, Munich 1970. Received for publication 30 November 1970 and in revised form 25 February 1971. Pyridoxamine was converted to active forms in red cells less efficiently. Pyridoxal entered red cells rapidly, equilibrating between plasma and cells within 1 min in the same ratio as pyridoxal formed inside red cells. Pyr...

BACKGROUND Vitamin B6 is present in various forms (vitamers) in the diet that need to be metabolized to pyridoxal phosphate (PLP), the active cofactor form of vitamin B6. In literature, the liver has been reported to be the major site for this conversion, whereas the exact role of the intestine remains to be elucidated. OBJECTIVE To gain insight into the role of the intestine in human vitamin...

BACKGROUND Non-enzymatic glycation is the addition of free carbonyl group of reducing sugar to the free amino groups of proteins, resulting in the formation of a Schiff base and an Amadori product. Dihydroxyacetone (DHA) is one of the carbonyl species which reacts rapidly with the free amino groups of proteins to form advanced glycation end products (AGEs). The highly reactive dihydroxyacetone ...