Identification of IgG and Fc-binding proteins in human seminal plasma and sperm.
Human seminal plasma contains two novel soluble proteins capable of binding IgG and Fc, but not Fab. The IgG- and Fc-binding proteins were identified by immunoblotting using IgG of various species, Fc and Fab fragments. Their estimated molecular sizes are 16-kD and 20-kD. The monoclonal antibody (MAb), Leu 11b, raised against Fc gamma RIII interacts with the 16-kD protein, whereas other mAbs (32.2, IV.3, and 3G8) raised against FcR did not. The 16-kD protein is capable of binding IgG of several species (human, mouse, rabbits, and goat), whereas the 20-kD protein interacted only with human IgG-Fc fragment. The 16-kD IgG and the 20-kD Fc-binding proteins were found in the PBS extract of human sperm. Human seminal plasma/sperm contain an IgG- and a Fc-binding protein with estimated Mr of 16 and 20 kD, respectively.
Kamada
M
M
Center for Biomedical Research, Population Council, New York, New York 10021.
Liang
Z
Z
Koide
S S
SS
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000032:analysis / Q000276:immunology; D015153:Blotting, Western; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D011961:Receptors, Fc / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D017452:Receptors, IgG; D012661:Semen / Q000276:immunology*; D013094:Spermatozoa / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG