Purification and Properties of Avian Growth Hormones

Growth hormone has been isolated from the pituitaries of four species of birds (chicken, duck, pigeon and turkey) and partially characterized. All four preparations are active in the tibia test. All elute from a Sephadex G-100 column with a Ve/Vo of about 2.0 and have similar characteristics when examined by disc electrophoresis. In addition, the amino acid contents of all four are similar, and resemble mammalian growth hormone in composition. The N-terminal amino acid sequence ofboth duck and pigeon growth hormones begin with the sequence Phe-Pro-Ala-Met-, which is virtually identical to the N-terminus of ovine and bovine growth hormone. Immunochemical studies (agar diffusion and radioimmunoassay) showed all bird growth hormones to be closely related to one another and to share antigenic determinants with mammalian and reptilian growth hormone. It is concluded that the growth hormone structure has been strongly conserved during evolution. (Endocrinology95: 1560, 1974)