Critical evaluation of a theory of molecular recognition using human insulin-like-growth-factor-I fragment 21-40 and its complementary peptide.
Using solid-phase methods we have synthesized human insulin-like-growth-factor-I (IGF-I) fragment 21-40 (IGF-I 21-40) and the peptide derived from the 5'----3' translation of the complementary nucleic acid of this peptide, 'I-FGI 20-40' (the complementary peptide). According to a recently proposed theory of molecular recognition, these two peptides should bind specifically to each other. We have tested this theory by using both solid- and solution-phase direct-binding assays for this complementary-peptide pair. We have also investigated the ability of I-FGI 20-40 to interfere with native IGF-I binding during radioimmunoassay (r.i.a.), radio-receptor (r.r.a.) assay and ligand-blot analysis of IGF-binding proteins. We have obtained no evidence of any interaction between IGF-I 21-40 and I-FGI 20-40 in either solid- or solution-phase assays. In addition, I-FGI 20-40 does not interfere in the assays used to detect IGF-I binding antibodies (r.i.a.), receptors (r.r.a.) or binding proteins (ligand blots). Our data therefore question the universality of this particular theory of molecular recognition.
Beattie
J
J
Hannah Research Institute, Ayr, Scotland, U.K.
Flint
D J
DJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002942:Circular Dichroism; D005260:Female; D006801:Humans; D018971:Insulin-Like Growth Factor Binding Protein 2; D007334:Insulin-Like Growth Factor I / Q000138:chemical synthesis / Q000737:chemistry* / Q000235:genetics; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry* / Q000235:genetics; D010455:Peptides / Q000138:chemical synthesis; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011487:Protein Conformation; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D017451:Receptors, Somatomedin
D002352:Carrier Proteins; D018971:Insulin-Like Growth Factor Binding Protein 2; D010446:Peptide Fragments; D010455:Peptides; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; C074298:human insulin-like-growth-factor-I (21-40); D007334:Insulin-Like Growth Factor I