Corpus luteum derived copper, zinc-superoxide dismutase serves as a luteinizing hormone-release inhibiting factor in sheep.
In the present study, we report the purification and characterization of a polypeptide from the sheep corpus luteum of pregnancy with a potent luteinizing hormone-release inhibiting factor (LH-RIF) bioactivity that stained as a single band in SDS-PAGE with an apparent molecular mass of 16000 Da. The amino acid sequences obtained after sequence analysis of peptides derived from the trypsin digestion of LH-RIF were subjected to a protein data bank search and were found to be identical with regions of sheep copper, zinc-superoxide dismutase (Cu,Zn-SOD). The measured mass of LH-RIF (15604.2+/-1.9 Da) was found to be similar to the theoretical mass of sheep Cu,Zn-SOD (15603.5 Da), with a disulfide bond and N acetylated alanine at the N-terminus. The inhibitory action of Cu,Zn-SOD on pulsatile LH secretion would suggest that this antioxidant may play an important role, either independently or in concert with some neurotransmitters, in the neuroendocrine regulation of sheep female reproductive function.
Al-Gubory
Kaïs H
KH
Institut National de la Recherche Agronomique, Unité de Recherches de Physiologie Animale, 78352 Jouy-en-Josas cedex, France. algubory@jouy.inra.fr
Huet
Jean-Claude
JC
Pernollet
Jean-Claude
JC
Martal
Jacques
J
Locatelli
Alain
A
D000818:Animals; D003338:Corpus Luteum / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008970:Molecular Weight; D011247:Pregnancy; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D013482:Superoxide Dismutase / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*
D007986:Luteinizing Hormone; D013482:Superoxide Dismutase