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Lopap (prothrombin activator protein) and derived peptides as promising tissue remodeling agents

Carvalho C1, Mesquita-Pasqualoto KF1, Alvarez-Flores MP1, Chudzinski-Tavassi AM1, Ayupe A C2, Reis E2

1 Laboratório de Bioquímica e Biofísica, Instituto Butantan, Brasil; 2 Departamento de Bioquímica, Instituto de Química Universidade de São Paulo, Brasil

Introduction: Lopap (Lonomia obliqua prothrombin activator protein) is a protein isolated from bristles of L. obliqua caterpillar. The recombinant form (rLopap) displays serine protease-like activity with procoagulant effect. Also, it acts directly on the endothelium promoting antiapoptotic effects and increasing the expression of molecules involved in inflamation. Lopap monomer has presented a similarity of 20 to 59% with lipocalin and additionally shares three motifs found in the lipocalin family. A small library of Lopap-derived peptides from these three motifs, after a rational approach using computational chemistry and chemometric methods, was synthetized and experimentally assayed. The peptides have reproduced the antiapoptotic effects previously observed in trials involving rLopap and endothelial cells. The lipocalin’s signature sequence was defined from motif 2. Computational chemistry and chemometric methods was used for a rational development of the new peptides from the lipocalin signature sequence. Objectives: Investigate the molecular target and intracellular signaling pathways involved in the antiapoptotic effect of Lopap and P4 as well as its derived peptides.
  Methods: The antiapoptotic potential was evaluated regarding the viability assay (MTT reduction) on human umbilical vein endothelial cells (HUVEC). In addition, microarray assay was carried out in order to discriminate changes in gene expression and to identify the main biochemical pathways involved in cytoprotective action. Results and Discussion: The peptides have reproduced the antiapoptotic effects previously observed in trials involving P4 and endothelial cells. The CCR1 and RECQL5 genes were differentially expressed. CCR1 corresponds to a chemokine transmembrane receptor protein G coupled, which is involved in tissue remodeling, proliferation and cytoprotection, and RECQL5 acts in DNA replication and repair. Furthermore, RECQL5 depletion can be associated with a low proliferation rate. So far, the findings have indicated Lopap and derived peptides as promising tissue remodeling agents.

Supported by FAPESP

2 - BIOCHEMISTRY 17th Annual Scientific Meeting of Instituto Butantan.