Post-translational modifications in glycosylation status during epididymal passage and significance in fertility of a 33 kDa glycoprotein (MEF3) of rhesus monkey (Macaca mulatta).
The present study reports data on post-translational modifications in the glycosylation status during epididymal passage and significance in fertility of a 33 kDa glycoprotein of rhesus monkey (Macaca mulatta), designated as MEF3 (monkey epididymal fluid protein 3). MEF3 exhibited strong affinity for N-linked alpha-D-mannose groups and O-linked N-Ac-galactosamine linkages in epididymal fluids and exhibited moderate affinity for N-Ac-glucosaminylated (wheat germ agglutinin), fucosylated (Tetragonolotus purpurea), and N-Ac-galactosamine (peanut agglutinin) residues on more mature corpus and caudal spermatozoa in a maturation-dependent manner on Western blots probed with specific biotinylated lectins. Polyclonal antiserum raised against affinity-purified MEF3 from caudal epididymal fluid (CEF) cross-reacted specifically with CEF and caudal sperm membrane of macaque and with Triton X-100 extract of ejaculated human spermatozoa, suggesting the existence of antigenically related components in both species. The tangled agglutination caused by anti-33 kDa serum of human spermatozoa, along with localization of MEF3 on entire sperm surface of epididymal and testicular sperm of monkey and human spermatozoa, suggest the significance of MEF3 in sperm function. The 100% inhibition of fertility of immunized female rabbits with this protein in vivo and inhibition of human sperm penetration in zona-free hamster eggs in vitro suggests the functional significance of MEF3 in fertility. Together, these results clearly indicate that MEF3 has potential significance as a target for antibodies that inhibit sperm function and fertility.
Chandra
Abhishek
A
Division of Endocrinology, Central Drug Research Institute, PO Box 173, Lucknow 226001, India.
Srinivasan
Kokattam Rama
KR
Jamal
Farrukh
F
Mehrotra
Puroshottam Kumar
PK
Singh
Ram Lakhan
RL
Srivastav
Archana
A
D000818:Animals; D001681:Biological Assay / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D006224:Cricetinae; D004822:Epididymis / Q000378:metabolism*; D005260:Female; D005298:Fertility / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D037102:Lectins / Q000378:metabolism; D008253:Macaca mulatta / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D011817:Rabbits; D013073:Sperm Agglutination; D013084:Sperm-Ovum Interactions / Q000502:physiology; D013094:Spermatozoa / Q000737:chemistry / Q000378:metabolism*
D006023:Glycoproteins; D007106:Immune Sera; D037102:Lectins