Etude cinetique de l’action de la lipase pancreatique sur des triglycerides en emulsion. Essai d’une enzymologie en milieu heterogene

摘要: Summary The purpose of this paper was to study the action pancreatic lipase (glycerol ester hydrolase, EC 3.1.1.3) on emulsified triglycerides. This type is an interesting example enzymatic process taking place in heterogeneous medium. It shown that: 1. Lipase adsorbed by its substrate and initial rate ( v ) reaction a function number enzyme molecules at interface. 2. By varying dilution triglyceride emulsion bile salts presence 0.1 M NaCl, linear Lineweaver-Burk representations are obtained from which paramaters V m arid K can easily be derived. However, abscissae representation, consequently values, remain undefined as long right substitute for concentration concept not found. Obviously, cannot used when insoluble state. 3. using two emulsions containing particles different size, it that does depend directly weight substrate. For same weight, amount experimental conditions. becomes higher average size decreases, depends area I experimentally determined with good accuracy techniques : centrifugation sucrose gradient counting according their electronic Coulter counter. 4. On other hand, inversely proportional total volume A 0 emulsion. Thus, adsorption may considered fully reversible our conditions take Langmuir's isotherms. “interface concentration” / , i.e. interfacial unit emulsion, playing, case lipase, role normally devoted (emulsion) corresponds certain value interface concentration. mean only significant variable process. Other variables such electrical charge molecular organization also play role. 5. supposed well-known influence during intraluminar phase digestion least partly related ability these substances favour reversibility