SEROLOGICAL RELATIONSHIPS AMONG β-LYSIN, PLAKIN, AND LEUKIN

Abstract

Donaldson, D. M. (Brigham Young University, Provo, Utah), R. S. Jensen, B. M. Jensen, and A. Matheson. Serological relationships among β-lysin, plakin, and leukin. J. Bacteriol. 88:–1049 1055. 1964.—β-Lysin is a substance which has been separated from normal serum and which is bactericidal for a variety of gram-positive bacteria including Bacillus subtilis. Purified β-lysin is not denatured at 97 C for 15 min. The bactericidal activity of six of nine β-lysin preparations was unaltered at 97 C for 30 min and was depressed 50% in the other three preparations. After 120 min at 97 C, the bactericidal activity was between 13 and 25% of normal. β-Lysin was completely inactivated at 120 C for 15 min. Antisera prepared in guinea pigs against purified rabbit β-lysin neutralized the bactericidal activities of purified β-lysin, normal rabbit serum, platelet extracts, and purified plakin. This serological relationship between β-lysin and plakin was also demonstrated by the observation that antisera against platelets neutralized the bactericidal activities of serum, platelet extracts, and purified β-lysin. When anti-β-lysin serum was tested against crude bactericidal extracts of leukocytes and purified leukin, no neutralization of these bactericidal substances was measurable. The results of this study are in accord with conclusions made in previous studies that platelets are a primary source of serum β-lysin and that leukocytes contribute little, if any, to this type of serum bactericidal activity. Ouchterlony tests, in combination with the neutralization studies, indicated that the antigen-antibody system involved in the neutralization of β-lysin may be a nonprecipitating system.