Interactions of bile salt micelles and colipase studied through intermolecular nOes.
Colipase is a small protein (10 kDa), which acts as a protein cofactor for the pancreatic lipase. Various models of the activated ternary complex (lipase-colipase-bile salt micelles) have been proposed using detergent micelles, but no structural information has been established with bile salt micelles. We have investigated the organization of sodium taurodeoxycholate (NaTDC) micelles and their interactions with pig and horse colipases by homonuclear nuclear magnetic resonance (NMR) spectroscopy. The NMR data supply evidence that the folding of horse colipase is similar to that already described for pig colipase. Intermolecular nuclear Overhauser effects have shown that two conserved aromatic residues interact with NaTDC micelles.
Dominguez
C
C
Unité de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13204 Marseille Cedex 20, France.
Sebban-Kreuzer
C
C
Bornet
O
O
Kerfelec
B
B
Chapus
C
C
Guerlesquin
F
F
D000595:Amino Acid Sequence; D000818:Animals; D001647:Bile Acids and Salts / Q000737:chemistry*; D003089:Colipases / Q000737:chemistry*; D006736:Horses; D008823:Micelles; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010179:Pancreas / Q000737:chemistry; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013552:Swine; D013657:Taurodeoxycholic Acid / Q000737:chemistry*
D001647:Bile Acids and Salts; D003089:Colipases; D008823:Micelles; D013657:Taurodeoxycholic Acid