An additional arginine-vasotocin-related peptide, vasotocinyl-Gly-Lys, in Xenopus neurohypophysis.
The neurohypophysis of Xenopus and that of Ranidae and Bufonidae contain hydrin 1 (vasotocinyl-Gly-Lys-Arg) and hydrin 2 (vasotocinyl-Gly), respectively. In order to test the aldosterone-releasing activity of arginine vasotocin (AVT) and hydrin 1, purification of these peptides from an acid-extract of the neurointermediate lobe of Xenopus laevis was performed using an ODS-silica cartridge and reverse-phase and ion-exchange HPLC columns. As a result, an additional AVT-related peptide was newly found. Amino-acid analysis revealed that this peptide is vasotocinyl Gly-Lys (AVT-GK). The aldosterone-releasing activity of AVT-GK was equivalent to that of hydrin 1 (AVT-GKR) and lower than that of AVT. Like AVT and AVT-GKR, AVT-GK were effective in stimulating water flux from the isolated urinary bladder of the toad. Since AVT-GK is regarded as an intermediate between hydrin 1 and hydrin 2 in terms of its C-terminal form, it was designated hydrin 1'.
Iwamuro
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Department of Biology, School of Education, Waseda University, Tokyo, Japan.
Hayashi
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Kikuyama
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D000450:Aldosterone / Q000378:metabolism; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002025:Bufonidae; D008969:Molecular Sequence Data; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000378:metabolism*; D011898:Ranidae; D001743:Urinary Bladder / Q000187:drug effects; D014668:Vasotocin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D014981:Xenopus / Q000378:metabolism*
D000596:Amino Acids; C080294:hydrin 1'; C060257:hydrin 1; C060258:hydrin 2; D000450:Aldosterone; D014668:Vasotocin