Elephant growth hormone. Isolation and characterization.
Growth hormone has been purified to homogeneity from elephant pituitary glands. It has 191 amino acids with two disulfide bridges and a single tryptophan residue. The somatotropin activity is only 15% when compared with the bovine hormone in the radioreceptor binding assay. From circular dichroism spectra alpha-helical content of elephant growth hormone is estimated to be 50%. Difference absorption spectra of the hormone suggest the presence of a hydrogen bond between the single Trp and a carboxylate ion.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D004220:Disulfides / Q000032:analysis; D004606:Elephants / Q000502:physiology*; D005260:Female; D013006:Growth Hormone / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008099:Liver / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000032:analysis*; D011247:Pregnancy; D011487:Protein Conformation; D011817:Rabbits; D011986:Receptors, Somatotropin / Q000378:metabolism; D013045:Species Specificity
D000596:Amino Acids; D004220:Disulfides; D011986:Receptors, Somatotropin; D013006:Growth Hormone