Submitted to: International Society For Trace Elements Research In Humans
Publication Type: Abstract Only
Publication Acceptance Date: September 26, 1998
Publication Date: N/A
Technical Abstract: Discovery of five naturally-occurring organoboron compounds, all antibiotics with a single boron atom critical for activity, established at least one biochemical role of boron. Vascular plants, diatoms, and some species of marine algal flagellates have acquired an absolute requirement for boron although the primary role remains unknown. The unusual nature of boron chemistry suggests the possibility of a variety of biological roles for boron. At physiological concentrations and pH, boron may react with one nitrogen group or one to four hydroxyl groups on specific biological ligands with suitable configuration and charge to form dissociable organoboron compounds or complexes. Suitable ligands include pyridine [e.g., NAD**+ or NADP] or flavin [e.g., FAD] nucleotides and serine proteases. For example, boron reacts with the cis adjacent hydroxyls on the ribosyl moiety of the nucleotides or, in the serine proteases, the nitrogen on the imidazole group of histidine or the hydroxyl group on the serine moiety. In vitro reversible inhibition by boron of activity of serine proteases or oxidoreductases that require pyridine or flavin nucleotides is well known. Therefore, a proposed essential role for boron is as a regulator of relevant pathways, including respiratory burst, that utilize these enzymes.