Release of Fc-receptors after streptococcal lysis induced by a lytic enzyme from Streptomyces globisporus

Streptolytic activities of a lytic enzyme from Staphylococcus hyicus

The LE IIIb fraction of the bacteriolytic enzyme from Staphylococcus hyicus could be isolated by ionic exchange chromatography and subsequent gel filtration. Isoelectric focusing of the highly purified enzyme preparation revealed an isoelectric point at pH 10.3. The lytic activity of LE IIIb on streptococci of various serogroups could be effectively analyzed with the help of an aggregometer and expressed as increase of transmittance at 546 nm. The streptococci differed in their LE IIIb lysis pattern, which was more pronounced with those of serological groups C and D and Streptococcus uberis. The lytic effect of the LE IIIb fraction was optimal at low molarity (0.01 mol/l) of the lysis buffer and reduced in the presence of HgCl2 and EDTA.

Mutanolysin-induced lysis of actinomyces pyogenes determined by aggregometry

The lytic activity of mutanolysin from Streptomyces globisporus on 42 cultures of Actinomyces pyogenes could be effectively analyzed in an aggregometer. It was expressed as increase of transmittance at 546 nm after 20 min and 2 h at 37 degrees C. The A. pyogenes cultures revealed no uniform lysis pattern. Most of the cultures were lyzed within 20 to 40 min at 37 degrees C, others were lyzed only moderately or weakly within 2 h of incubation. The lytic activity was optimal at low (0.01 mol/l) molarity of the lysis buffer between pH 5.7 and 7 and could be inhibited by HgCl2.A. pyogenes was not lyzed by lysostaphin or lysozyme.

Novel complex formed between a nonproteolytic cell wall protein of group A streptococci and alpha 2-macroglobulin

Binding of 125I-labeled alpha 2-macroglobulin (alpha 2M) to streptococci belonging to serological groups A, B, C, and G was studied. Streptococci of groups A and G interacted only with native alpha 2M, and those of group C reacted only with alpha 2M-trypsin complex. Binding of alpha 2M to group A streptococci was saturable and reversible. The dissociation constant was 2.02 X 10(-7) M, and the number of binding sites was calculated to be 18,000 per streptococcus. The alpha 2M-binding protein could be solubilized by treatment of group A streptococci with a murolytic enzyme and subsequently purified by affinity chromatography and high-pressure liquid chromatography. The purified protein was homogeneous on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had a molecular weight of 78,000. It possessed no proteolytic activity and interacted with native alpha 2M in Western blots (immunoblots). Interaction of purified binding protein with alpha 2M led to a change in the conformation of alpha 2M similar to that obtained by alpha 2M-protease complexes. Reversible binding of a nonproteolytic streptococcal component of alpha 2M is thus a novel feature of alpha 2M reactivity.

Effective murolytic solubilization of streptococcal-group-specific antigen

Streptococcal-group-specific antigens were solubilized with a murolytic enzyme contained in the culture supernatant of Streptomyces globisporus. This facilitated the effective serogrouping of streptococci from humans and animals.