Physico-chemical characterization of the main factors affecting the mode of action of liver alcohol dehydrogenase immobilized on nylon tubing.
Alcohol dehydrogenase (ADH) from horse liver (EC 1.1.1.1), cross-linked through the bifunctional reactive glutaraldehyde, onto nylon tubing was immobilized (35 micrograms cm-2 internal surface of nylon tubing). ADH inactivation kinetics of the immobilized enzyme are of first order (t1/2 = 84.3 h, k = 8.2 x 10(-3) h-1 at 5 degrees C; t1/2 = 2.6 h, k = 0.26 h-1 at 50 degrees C). The activity versus pH profile points to a smaller effect of pH on the activity of the enzyme, which is the case of ADH in solution, explicable on the basis of limitations to proton diffusion towards/from the support. A limiting effect to free external diffusion of the substrate (products) towards/from the support was observed; this effect seems to determine the effective kinetic behaviour of immobilized ADH.
Roig
M G
MG
Departmento de Quimica Fisica, Facultad de Farmacia, Universidad de Salamanca, Spain.
Bello
J B
JB
De Celis
C
C
Cachaza
J M
JM
Kennedy
J F
JF
D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D009757:Nylons; D009994:Osmolar Concentration; D013696:Temperature
D004800:Enzymes, Immobilized; D009757:Nylons; D000426:Alcohol Dehydrogenase