Biocatalytic formation of synthetic melanin: The role of vanadium haloperoxidases, L-DOPA and iodide

Add time:08/24/2019    Source:sciencedirect.com

The vanadium haloperoxidase (V-HPO) enzyme, extracted from the brown alga Laminaria saccharina, is able to catalyze the formation of a black precipitate, using as precursor the amino acid l-dopa in the presence of hydrogen peroxide and iodide, in one-pot synthesis. The l-dopa oxidation is a multistep reaction with a crucial role played by the iodide in the enzyme catalyzed peroxidative production of dopachrome, a well known intermediate in the synthesis of melanin. Dopachrome is then converted to a synthetic form of melanin through a polymerization reaction. Factors, such as buffer composition and pH, influence significantly the reaction first steps, but further steps of melanin production are hardly influenced. The biosynthetic melanin produced through the combination V-HPO/I/H2O2, was characterized by several spectroscopic techniques (UV–vis and FT-IR) as well as XRD. Moreover, this biopolymer is light sensitive, decomposing into oligo- and monomeric units. Scanning electron microscopy (SEM) imaging showed different morphologies when compared with commercial available melanin. The biosynthetic production of melanin can have a wide range of applications from photosensitive cells to biomedicine with the advantage of being produced under eco-friendly and mild conditions.

We also recommend Trading Suppliers and Manufacturers of VANADIUM IODIDE (cas 15513-84-5). Pls Click Website Link as below: cas 15513-84-5 suppliers

Prev:Coordination environment changes of the vanadium in vanadium-dependent haloperoxidase enzymes☆
Next:ReviewProbing the synthetic protocols and coordination chemistry of oxido-, dioxido-, oxidoperoxido-vanadium and related complexes of higher nuclearity)