title: ZP-binding peptides identified via phage display stimulate production of sperm antibodies in dogs.
abstract: Zona pellucida (ZP) glycoproteins play a central role in sperm-oocyte binding and fertilization. Sperm protein sequences that are involved in sperm-ZP recognition and have an important role in fertilization represent attractive targets for development of contraceptive vaccines, yet are currently unknown. To identify peptide sequences that recognize and bind to ZP proteins, we developed a novel selection procedure from phage display libraries that utilizes intact oocytes surrounded by ZP proteins. The major advantage of this procedure is that ZP proteins remain in their native conformation unlike a selection protocol previously published that utilized solubilized ZP on artificial solid support. Several peptides of 7 and 12 amino acids with binding specificity to canine ZP proteins were identified. Four of them (LNSFLRS, SSWYRGA, YLPIYTIPSMVY, and NNQSPILKLSIH) plus a control ZP-binding peptide (YLPVGGLRRIGG) from the literature were synthesized and tested for antigenic properties in dogs. NNQSPILKLSIH peptide stimulated production of anti-peptide antibodies. These antibodies bind to the acrosomal region of the canine sperm cell, demonstrating ability to act as sperm antibodies. The identified ZP-binding peptides (mimicking sperm cell surface antigens) may be useful in the design of immunocontraceptive agents for dogs.
authors.affiliation: Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36830, USA. samoiti@auburn.edu
authors.forename: Tatiana I
authors.initials: TI
authors.lastname: Samoylova
authors.forename: Nancy R
authors.initials: NR
authors.lastname: Cox
authors.forename: Anna M
authors.initials: AM
authors.lastname: Cochran
authors.forename: Alexandre M
authors.initials: AM
authors.lastname: Samoylov
authors.forename: Brenda
authors.initials: B
authors.lastname: Griffin
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Baker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000097:blood / Q000378:metabolism; D000917:Antibody Formation / Q000187:drug effects*; D000954:Antigens, Surface / Q000032:analysis; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D003269:Contraception, Immunologic / Q000662:veterinary; D004285:Dogs / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D004527:Egg Proteins / Q000276:immunology / Q000378:metabolism; D005260:Female; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology*; D019151:Peptide Library; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism; D013094:Spermatozoa / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D015044:Zona Pellucida / Q000378:metabolism*; D000072216:Zona Pellucida Glycoproteins
chemical_list: D000906:Antibodies; D000954:Antigens, Surface; D002352:Carrier Proteins; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D019151:Peptide Library; D011956:Receptors, Cell Surface; D000072216:Zona Pellucida Glycoproteins