Modification of a phospholipid-stabilised emulsion interface of bile: effect on pancreatic lipase activity

Fillery-Travis, Annette and Wickham, M. and Garrood, M. and Leney, J. and Wilson, P. D. G. (1998) Modification of a phospholipid-stabilised emulsion interface of bile: effect on pancreatic lipase activity. Journal of Lipid Research, 39 (3). pp. 623-632. ISSN 0022-2275

Full text is not in this repository.

Abstract

Lipase is activated by binding to an insoluble emulsified or aggregated substrate. The extent of binding is related to the physicochemical as well as the compositional structure of the interface, the quality of the interface. ‘Quality’ is as yet undefined but thought to contain contributions from electrostatic interactions, orientation of substrate, and hydration forces. To investigate the electrostatic and compositional factors we have used olive oil-in-water emulsions prepared with phosphatidylcholine and four bile salts of varying hydrophobicities. By measurement of the droplet zeta potential we have monitored semi-quantitatively the incorporation of bile salts within the interface. No correlation was found between droplet surface charge as monitored by the zeta potential and lag phase. The duration of the observed lag phase was found to be inversely related to the degree of incorporation of the bile salts. Simultaneously there was evidence of lipase binding to monomeric bile salts, reducing its availability for adsorption. Calcium ions reduced the surface charge but there was no correlation with lag phase duration. The evidence presented here agrees with a more specific role for calcium ions, i.e., the formation of a new catalytically active enzyme complex, (enzyme)–(mixed micelle)–(calcium ion).

Item Type: Article
Research Areas: A. > Work and Learning Research Centre
Item ID: 17729
Depositing User: Paul Stapleton
Date Deposited: 29 Sep 2015 09:22
Last Modified: 09 May 2017 11:04
URI: http://eprints.mdx.ac.uk/id/eprint/17729

Actions (login required)

Edit Item Edit Item