title: Studies in bile salt solutions. Deoxycholate stimulation of human milk lipase.
abstract: Stimulation of human milk lipase by deoxycholate and its taurine and glycine conjugates was demonstrated by measuring the esterolysis reaction of 4-nitrophenylacetate. The steroidal surfactants did not bind strongly to the polar substrate but they did bind effectively to a hydrophobic site on the enzyme and these bile salt-enzyme complexes were effective catalysts. These results are compared with those for stimulation of the enzyme by cholate surfactants and it has been demonstrated that the absence of a 7 alpha-OH substituent on the steroid nucleus does not prevent stimulation of either the esterolytic or lipolytic activity of the enzyme.
mesh_terms: D003840:Deoxycholic Acid / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D006002:Glycodeoxycholic Acid / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D008049:Lipase / Q000378:metabolism*; D008895:Milk, Human / Q000201:enzymology*; D009596:Nitrophenols / Q000378:metabolism; D013657:Taurodeoxycholic Acid / Q000494:pharmacology
chemical_list: D009596:Nitrophenols; D003840:Deoxycholic Acid; D006002:Glycodeoxycholic Acid; D013657:Taurodeoxycholic Acid; C008642:4-nitrophenyl acetate; D008049:Lipase