Glutamate substitution for glutamine at position 5 or 6 reduces somatostatin action in the eel intestine.
Isolating a new somatostatin-like peptide from eel gut, the active residues to potentiate somatostatin action in the eel intestine were determined. In the newly-isolated peptide, the 5th or 6th Gln of the eel somatostatin (eSS-25II) was replaced with Glu. Although this peptide also enhanced the short-circuit current (Isc) across the intestine of the seawater eel, higher concentrations (approximately 30 fold) were required to obtain the same effects as eSS-25II. Since the Isc is due to active Cl- transport, this indicates that a structure formed by Gln-Gln residues at position 5 and 6 potentiates the somatostatin action to enhance ion and water transport across the intestine of the eel.
Uesaka
T
T
Laboratory of Physiology, Faculty of Integrated Arts and Sciences, Hiroshima University, Japan.
Yano
K
K
Yamasaki
M
M
Ando
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004524:Eels; D018698:Glutamic Acid / Q000235:genetics / Q000378:metabolism*; D005973:Glutamine / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D008969:Molecular Sequence Data; D013004:Somatostatin / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D005973:Glutamine; D018698:Glutamic Acid; D013004:Somatostatin