Immunological characteristics of beta-N-acetylglucosaminidase from human seminal plasma
Gupta, G.S.; Agarwal, P.
Indian Journal of Biochemistry and Biophysics 19(1): 37-40
1982
ISSN/ISBN: 0301-1208 PMID: 7106816 Document Number: 192690
Immune response of .beta.-N-acetylglucosaminidase (EC 3.2.1.30) (.beta.-NAG) from human seminal plasma was studied in rabbits. Two precipitin lines were observed by immunoelectrophoresis and Ouchterlony gel-diffusion techniques when anti-.beta.-NAG serum cross-reacted with seminal plasma and purified enzyme. Both the precipitin bands of Ouchterlony plates showed residual enzyme activity when allowed to incubate with naphthol As-Bi-acetyl-.beta.-glucosaminide as substrate and coupled with fast GBC [Garnet Borden C (salt)]. Excess antigen and antibody tests revealed 33 and 39% inhibition of enzyme activity, respectively, suggesting inhibitory antibodies in anti-.beta.-NAG serum. Lineweaver-Burk plots of .beta.-NAG in presence of anti-serum or IgG showed that .beta.-NAG is inhibited by steric hindrance. Failure of cross-reaction of rat, goat and bovine testicular or epididymal extracts with seminal plasma anti-.beta.-NAG-serum suggested that human semen .beta.-NAG is species specific. Seminal plasma-anti-.beta.-NAG serum cross-reacted with monkey testicular and human sperm acrosomal extracts, proving that human seminal-plasma .beta.-NAG is immunologically identical to the human acrosomal and testicular enzyme from sub-human primates. Immunofluorescence studies indicated that .beta.-NAG of sperm is localized in the head region of acrosome.