Immunoglobulin G proteolytic activity of Actinobacillus actinomycetemcomitans

Abstract

Actinobacillus actinomycetemcomitans produces a protease to human immunoglobulin G that is an important evasion mechanism. In this study, the proteolytic activity of A. actinomycetemcomitans strain ATCC 43718 on human immunoglobulin G associated with culture supernatant concentrations, the growth period and the period of incubation with immunoglobulin G were evaluated by an enzyme linked immunosorbent assay. The protease fraction was detected by Sephadex G 150 chromatography. The results showed that A. actinomycetemcomitans produced a protease to human immunoglobulin G in the culture supernatant, and the highest activity was achieved witen the concentration was 27.5 μg protein/mL, after culturing for 72 hours and incubating with IgG for 24 hours. The molecular mass of the protease active fraction was from 43 to 150 kDa.