Análise dos constituintes de baixa massa molecular no veneno de Lachesis muta

Abstract

Snakebite accidents are a serious public health problem neglected in tropical countries. In Brazil, the Northern Region has the largest number of cases and snakes from Lachesis genus are responsible for the most serious accidents and the highest number of deaths. Victims of Lachesis envenoming have bite site damage, bleeding and, in severe cases, hypotension. Proteomic and transcriptomic studies report the presence of bradykinin potentiating peptide (BPPs) in L. muta venom, however, there are no data in the literature describing their purifications and identifications. The objective of this work is to identify and characterize angiotensin-converting enzyme inhibitors in the low molecular weight portion of Lachesis muta venom. For this lyophilized L. muta venom was dissolved in ammonium acetate buffer and filtered by centrifugation for size fractionating, using a 10 kDa centrifugal filter unit. The low molecular weight fraction was then chromatographed by RP-HPLC using a C18 column. Twelve fractions were collected and four were tested in fluorimetric assays using ACE as an enzyme and Abz-FRK(Dnp)P-OH as substrate. These fractions present peaks with retention time similar to the peaks that contained BPPs of other snake venoms. In addition, four fractions presented 100% inhibition of the catalytic activity of ACE over the FRET substrate. Based on these results, and due to other data in the literature describing the presence of BPPs in L. muta venom, is possible that it may contain BPPs. For confirmation of this hypothesis, the next step will be to perform analysis by mass spectrometry aiming to determine the primary sequences of the peptides present in each fraction.