Isolation and characterization of a variant somatostatin-14 and two related somatostatins of 34 and 37 residues from lamprey (Petromyzon marinus).

摘要: Three major forms of somatostatin were isolated from pancreas the lamprey (Petromyzon marinus). One two is a 14-residue (SS-14) having sequence AGCKNFFWKTFSSC. The homologous substitution Ser for Thr in position 12 first example SS-14 vertebrate preprosomatostatin gene I divergent sequence. longest form 37 residues length (SS-37) and has ALRAAAVAGSPQQLLPLGQRERKAGCKNFFWKTFSSC. A 34-residue (SS-34) identical but truncated at single Arg residue 3 SS-37 was also isolated. yields three (0.43 nmol/g), SS-34 (134 (51.5 nmol/g). identification this nested series somatostatins suggests that prosomatostatin processing more closely resembles observed procholecystokinin than mammalian or other piscine prosomatostatins. Somatostatin-producing cells identified by immunostaining using antiserum against anti-serum SS-14.