Inhibition mechanism of human salivary α-amylase by lipid transfer protein from Vigna unguiculata. (April 2020)

• Record Type: Journal Article
• Authors: da Silva, Flávia Camila Vieira; Pessoa Costa, Evenilton; Moreira Gomes, Valdirene; de Oliveira Carvalho, André
• Is Part Of: Computational biology and chemistry. Volume 85(2020)
• Publication Date: 2020-04
• Subjects: αG74-N91 synthetic peptide comprehending the amino acids G74 to N91 from VuLTP1.1 -- ΔG Gibbs free energy -- I-2 α-amylase/trypsin inhibitor from Eleusine coracana -- HOE-467A tendamistat α-amylase inhibitor from Streptomyces tendae -- HSA human salivary α-amylase -- Kd dissociation constant -- LTP1s lipid transfer proteins from family one -- N29-I47 synthetic peptide comprehending the amino acids N29 to I47 from VuLTP1.1 -- N29-I47mQ synthetic peptide N29-I47 in which the Arg39 was replaced by a Gln -- PPA porcine pancreatic α-amylase; Enzyme -- Cowpea -- Inhibitor -- Docking -- Modeling; Chemistry -- Data processing -- Periodicals; Biology -- Data processing -- Periodicals; Biochemistry -- Data processing; Biology -- Data processing; Molecular biology -- Data processing; Periodicals; Electronic journals; 542.85
• DOI: 10.1016/j.compbiolchem.2019.107193
• Languages: English
• ISSNs: 1476-9271

Abstract

Graphical abstract: Highlights: HSA is inhibited by Vu LTP1.1 because the obstruction of the carbohydrate biding cleft. Vu LTP1.1 Arg39 is burrowed into the active site of the HSA. Vu LTP1.1 Arg39 interacts with the Asp300 of HSA catalytic site by a hydrogen bond. Abstract: Vu LTP1.1, a LTP1 from Vigna unguiculata, inhibits 78.1 % of the human salivary α-amylase (HSA) activity at 20 μM. We had performed a correlation study between Vu LTP1.1 structure and HSA inhibitory activity and showed that two Vu LTP1.1 regions are responsible for HSA inhibition. In one of them we had characterized the crucial importance of an Arg39 for inhibition. In this work, we analyzed the Vu LTP1.1-HSA interaction by protein-protein docking to understand the most probable interaction model and the mechanism of HSA inhibition by Vu LTP1.1. The Vu LTP1.1 tertiary structure quality and refinement as well as the docking assay between Vu LTP1.1 and HSA were done by bioinformatic programs. HSA inhibition occurs by direct interaction of the Vu LTP1.1 with the HSA causing the obstruction of the carbohydrate biding cleft with Gibbs free energy of -18.5 Kcal/mol and the dissociation constant of 2.6E −14 M. The previously identified Arg39 of Vu LTP1.1 is burrowed into the active site of the HSA and there it interacts with the Asp300 of HSA catalytic site by a hydrogen bond. We had confirmed the importance of the Arg39 of Vu LTP1.1 for the HSA inhibition which interacts with the Asp300 at the HSA active site. I-2, a LTP-like peptide, presents the same HSA inhibition pattern that Vu LTP1.1, which indicates that the inhibition mechanism of the LTPs towards α-amylase is very similar. For the best of our knowledge, it is the first time that the HSA inhibition mechanism was understood and described for the LTP1s using Vu LTP1.1 and I-2 as prototype inhibitors.