RESUMO
Objective: The objective of this research was to study plant cell wall degradation enzymes from Fusarium sp. Q7-31T. Methods: Strain was cultured in liquid medium with 1% (W/V) peptone as nitrogen source, 0.5% (W/V) oat straw as carbon source, 120 r/min shaking at 20 °C for 3 days. The endoglucanase Egn21 was purified by using Sephacry S-100 chromatography and DEAE-sepharose ion-exchange column chromatography. Then the enzymatic properties and MADIL-TOF-TOF identification were analyzed. Results: The molecular weight and isoelectric point (pI) of Egn21 was 44.25 kDa and 4.91, respectively. Egn21 had optimal activity with carboxymethyl cellulose at 40 °C and pH 6.0, stable at 45 °C and pH between 5.0 and 8.0, inhibited by Fe2+, Ca2+, K+, Na+, Mn2+ and inactivated by Hg2+, whereas Co2+, Zn2+ and Mg2+ had no effect. Conclusion: The enzymatic properties and MADIL-TOF-TOF results suggested that Egn21 belongs to GH5 family.
Assuntos
Celulase/química , Celulase/isolamento & purificação , Proteínas Fúngicas/química , Fusarium/enzimologia , Celulase/genética , Celulase/metabolismo , Cromatografia em Gel , Cromatografia por Troca Iônica , Estabilidade Enzimática , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/química , Fusarium/genética , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Cinética , Espectrometria de Massas , Peso Molecular , TemperaturaRESUMO
Glycoprotein (GP) 2a was a minor structural protein of porcine reproductive and respiratory syndrome virus (PRRSV) and was one of crucial proteins for PRRSV to bind cell receptor, which indicated that there were neutralizing epitopes on GP2a. In the present work, we used mouse anti-GP2a41-208aa serum and one GP2a41-208aa specific monoclonal antibody (McAb) to identify B-cell epitopes of GP2a by peptide-based ELISA. A liner B-cell epitope F194PTPGSRPKLHDFQQ208 was identified. However, the results of virus neutralization experiment showed that the McAb could not reduce the titers of PRRSV, which indicated that the identified epitope was not the neutralizing epitope of PRRSV. While the amino acid sequence of this epitope was conserved in North American (type 2) PRRSV, which suggested that this epitope might be diagnostic potential for type 2 PRRSV strains. In conclusion, our present work identified a new epitope on GP2a and this epitope might be diagnostic potential for type 2 PRRSV strains.