Ka. Krishnan et al., PURIFICATION AND PARTIAL CHARACTERIZATION OF ISOFORMS OF LUTEINIZING-HORMONE FROM THE CHICKEN PITUITARY-GLAND, Comparative biochemistry and physiology. B. Comparative biochemistry, 108(2), 1994, pp. 253-264
Isoforms of chicken luteinizing hormone (cLH) were isolated from chick
en pituitaries by differential extraction, sequential chromatography o
n HPLC cation- and anion-exchange columns, and gel-filtration chromato
graphy. Three purified isoforms of the cLH had high biological potency
in the chicken granulosa cell LH bioassay (4.21-7.4 x NIH-LH-S1 U/mg)
. One cLH isoform without detectable biological activity showed substa
ntial immunological activity in a homologous cLH radioimmunoassay. The
cLH isoforms contained negligible follicle-stimulating hormone activi
ty, but some contained thyroid-stimulating hormone activity. The appar
ent molecular weight of cLH was 37,000 Da, and the holoprotein consist
ed of subunits with a molecular weight of approximately 17,000 Da.