A fragment of triosephosphate isomerase competes with the vasoactive intestinal polypeptide (VIP) for binding to the VIP receptor.
A 28-residue N-terminal fragment of triosephosphate isomerase, TIM(1-28), has been purified from porcine upper intestine. It competes with VIP for binding to the VIP receptor on rat liver plasma membranes with an IC50 value of 2.8 mM, about 1000 times higher than that for VIP binding to the membranes. Except for a single positional identity and the number of amino acid residues, the amino acid sequences of TIM(1-28) and VIP are unrelated as regards primary structure. However, the ability to bind to the same receptor site may indicate common three-dimensional structural properties.
Gafvelin
G
G
Department of Biochemistry II, Karolinska Institute, Stockholm, Sweden.
Bergman
T
T
Andersson
M
M
Persson
B
B
Jörnvall
H
H
Mutt
V
V
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D008099:Liver / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism*; D011487:Protein Conformation; D051381:Rats; D011919:Rats, Inbred Strains; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism*; D018005:Receptors, Vasoactive Intestinal Peptide; D013552:Swine; D014305:Triose-Phosphate Isomerase / Q000302:isolation & purification / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D010446:Peptide Fragments; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide; D014305:Triose-Phosphate Isomerase