Kinetics as a Function of Temperature of Lipase, Trypsin, and Invertase Activity From ?70 to 50�c.(?94 to 122�f.)

Abstract

Contribution 5'0. 209 from the

Cryo-bioorganic chemistry: molecular interactions at low temperature

“…Freezing of the solutions caused a 20-fold and 3-fold decrease of rates, respectively. Similar effects have been obtained by Sizer and Josephson [10], who investigated the kinetics of hydrolyses catalyzed by lipase, trypsin and invertase enzymes over the temperature range from 50 to −24.5, −15 and − 18°C. The substrates were the followings: tributyrin, casein and sucrose.…”

“…A survey of reactions in frozen systems can be found in [1][2][3][4][5][6]. Because the early works were concerned with the cold storage of foods and it was realized that the role of enzymes is a decisive factor in food preservation, these studies concentrated mainly on enzyme action at low temperatures [7][8][9][10]. Comparison of frozen and undercooled solutions of enzyme systems revealed that below the freezing point of the reaction mixture there was a significant decrease of rate in the kinetics of frozen solutions compared with the undercooled ones or with the theoretical values obtained by extrapolation of the Arrhenius plots.…”

The Effect of Temperature on the Conversion of Protochlorophyll to Chlorophyll a in Etiolated Barley Leaves.

“…The fact that the reaction proceeds at low temperatures has been taken as evidence against the enzymatic nature of the reaction. This may not be strictly valid, inasmuch as enzymes are known to possess appreciable activity at low temperatures (4,16,17). The temperature coefficients of the enzymatic reactions are, however, of an entirely different order of magnitude from those found for the protochlorophyll transformation.…”

Modelling the kinetics of enzyme-catalysed reactions in frozen systems: the alkaline phosphatase catalysed hydrolysis of di-sodium-p-nitrophenyl phosphate

“…This is less common for enzyme-catalysed reactions in non-cellular systems as the rate-enhancing effect of freeze-concentration is mostly overbalanced by the ratedepressing effect of a freeze-induced increase in salt concentration with the accompanying change in pH and ionic strength (Fennema, 1975a). A distinct depression in activity that is more pronounced than that predicted by Arrhenius equation has been observed for the activities of enzymes such as invertase, proteinase and lipase, trypsin, alkaline phosphatase and peroxidase in the subfreezing temperature range in non-cellular systems (Fennema, 1975a;Lund, Fennema, & Powrie, 1969;Maier, Tappel, & Volman, 1954;Mullenax & Lopez, 1975;Sizer & Josephson, 1942). In general, significant deviation from the Arrhenius equation is observed for the kinetics of enzyme-catalysed reactions in the subfreezing temperature range, even when freezing does not occur (Fennema, 1975a).…”