Proteinase inhibition using small Bowman-Birk-type structures

Bowman-Birk inhibitors (BBIs) are cysteine-rich and highly cross-linked small proteins that function as specific pseudosubstrates for digestive proteinases. They typically display a "double-headed" structure containing an independent proteinase-binding loop that can bind and inhibit trypsin, chymotrypsin and elastase. In the present study, we used computational biology to study the structural characteristics and dynamics of the inhibition mechanism of the small BBI loop expressing a 35-amino acid polypeptide (ChyTB2 inhibitor) which has coding region for the mutated chymotrypsin-inhibitory site of the soybean BBI. We found that in the BBI-trypsin inhibition complex, the most important interactions are salt bridges and hydrogen bonds, whereas in the BBI-chymotrypsin inhibition complex, the most important interactions are hydrophobic. At the same time, ChyTB2 mutant structure maintained the individual functional domain structure and excellent binding/inhibiting capacities for trypsin and chymotrypsin at the same time. These results were confirmed by enzyme-linked immunosorbend assay experiments. The results showed that modeling combined with molecular dynamics is an efficient method to describe, predict and then obtain new proteinase inhibitors. For such study, however, it is necessary to start from the sequence and structure of the mutant interacting relatively strongly with both trypsin and chymotrypsin for designing the small BBI-type inhibitor against proteinases.

Actualizaciones de Campylobacter. Especies termofilas de Campylobacter: I. Aspectos historicos, taxonomia y diagnostico de laboratorio. / Updating in Campylobacter. Thermofile species of Campylobacter: I. Historical,taxonomy and laboratorial diagnosis aspects

Se sistematiza la informacion existente sobre especies termofilas de Campylobacter, basado en la revision de 55 autores sobre el tema que incluye evolucion historica, corrientes taxonomicas y diagnostico de laboratorio

Isolamento de "Campylobacter fetus" ssp. "jejuni" em criancas normais e com diarreia. / Isolation of Campylobacter fetus ssp. jejuni in normal and diarrheal children

A frequencia de isolamento de Campylobacter fetus ssp. jejuni nas fezes de criancas normais e com diarreia foi estudada na cidade de Sao Paulo. Foram estudadas 125 criancas divididas em tres grupos: 1) Controle; 2) Diarreia aguda e 3) Diarreia cronica.A frequencia de isolamento de campylobacter foi a seguinte: grupo 1: 5,3%; grupo II: 9,3% e grupo III: 6,1%.Estes dados permitem-nos enfatizar a necessidade da pesquisa de Campylobacter de forma rotineira em criancas com diarreia aguda