Docking Interaction of Chromium(III) Picolinate and Chromate Ion Compounds with Protein Tyrosine Phosphatase as Insulin Receptors

Abstract: The Chromium(III) compounds have been shown to reduce glucose levels in type 2 diabetics, however, the role of chromium(III) in glucose metabolism cannot be clearly explained. Based on in vitro studies, there are two opinions regarding the mechanism of the role of chromium(III), the first opinion states that the chromium(III) that enters the body directly interacts with protein tyrosine phosphatase (PTP). Second opinion, chromium(III) which enters the body undergoes oxidation to become chromium(VI), and chromium(VI) interacts with PTP. To determine the mechanism that occurs, modeling using chromium(III) picolinate as a chromium(III) complex and chromate ion as chromium(VI) interacts with PTP. The structure optimization compounds was carried out using the Hartree-Fock computation method based on the 6-31G(d). The interaction study was studied using the Autodock Vina and ONIOM methods. The interaction results of chromium(III) picolinate docking interact with Leu(13), Ile(16), Ser(47), Trp(49), Asn(50), and Tyr(131) with interaction energy of -7.00 kcal.mol-1. Chromate ion interacts with amino acids Leu(13), Gly(14), Ile(16), Cys(17) and Arg(18) with an interaction energy of -4.10 kcal.mol-1. The result of interaction energy of chromium(III) picolinate is lower than that of chromate ion, which indicates that the interaction of chromium(III) picolinate with PTP is better than chromate ion.