Space-time and Entropic Characterization of Aspergillus oryzea α-amylase Catalyzed Reaction

Abstract

Aims: The aims of this investigation were to determine: 1) the distribution of time and time-dependent events in a catalytic cycle, 2) maximum and minimum (average) interparticle distance between interacting molecules, 3) quantify the entropic term, and 4) elucidate the implication of entropic “barrier”. Methodology: The study design is theoretical and experimental. The place of research was Research Division of Ude International Concepts Limited (RC 862217), B.B. Agbor and Owa Alizomor Sec. Sch. Owa Alizomor, Delta State, Nigeria. The research spanned a period of ~ 1.5 years with stoppages between 20-07-2015 and 02-12-2016. Bernfeld method of enzyme assay was used. Data generated from assay of enzyme and calculated data were fitted to the models to determine the desired parameters. Results: The catalytic orientation time ranging from 4.78-43.78 ms corresponds to value of [S] ranging from 22.04 g/l-3 g/l. Average time for the formation of product per molecule of enzyme, 1/á k2 ñ = 2.58 ms. Translational entropy, TE = 28.95±0.03 J/mol.K. The entropy of dilution, DS¥dil, at infinite dilution = 64.75±1.51 J/mol.K. TE (TE¥) when tc = 0, is = 6.27±1.13 kJ/mol.K. The minimum interparticle distance at maximum concentration of substrate, lm = 5.3142±0.06 exp (-8) m. Conclusion: Different aspects of catalytic action include transit before effective collision, catalytic orientation, catalytic transformation of product and product release. Each aspect has its duration. The time (tc) spent in catalytic transformation of substrate and release of product is < the time (reciprocal of rate constant, 1/k2) taken to yield a product by a molecule of an enzyme. (1/á k2 ñ) - á tc ñ = catalytic orientation time. Period of transit is « period within the active site. TE, unlike entropic “barrier” due to the state of dilution, promotes catalytic function.