title: Superiority of an antagonist of the luteinizing hormone releasing hormone with emphasis on arginine in position 8, named Argtide.
abstract: In the research for more potent antagonists of the luteinizing hormone releasing hormone (LHRH), 13 new peptides with emphasis on arginine in position 8 were designed, synthesized and tested for anti-ovulatory activity (AOA). Two very potent analogs were achieved. N-Ac-D-3-Qal, D-pClPhe, D-3-Pal, Ser, cis-PzACA1a, D-PicLys, Leu, Arg, Pro, D-AlaNH2 showed 63% AOA at 0.125 microgram and 89% at 0.25 microgram, and an ED50 of 30.8 +/- 0.59 and presently may be the most promising antagonist reported. It is named Argtide. N-Ac-D-3-Qal, D-pClPhe, D-3-Pal, Ser, cis-PzACA1a, D-PicLys, Val, Arg, Pro, D-AlaNH2 showed 18% AOA at 0.125 microgram. Arg8 in antagonists may be significant for receptor binding.
authors.affiliation: Institute for Biomedical Research, University of Texas, Austin 78712.
authors.forename: A
authors.initials: A
authors.lastname: Janecka
authors.forename: A
authors.initials: A
authors.lastname: Ljungqvist
authors.forename: C
authors.initials: C
authors.lastname: Bowers
authors.forename: K
authors.initials: K
authors.lastname: Folkers
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000737:chemistry*; D006224:Cricetinae; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides; D051381:Rats; D011966:Receptors, LHRH / Q000378:metabolism
chemical_list: D009842:Oligopeptides; D011966:Receptors, LHRH; C071339:argtide; C071340:N-acetyl-3-(3-quinolyl)alanyl-3-(4-chlorophenyl)alanyl-3-(3-pyridyl)alanyl-seryl-3-(4-pyrazinylcarbonylaminocyclohexyl)alanyl-N(epsilon)picolinoyllysyl-valyl-arginyl-prolyl-alaninamide; D007987:Gonadotropin-Releasing Hormone; D001120:Arginine