We are testing a new theory of temperature sensitivity of biological systems called macromolecular rate theory (MMRT). Vic Arcus has led this work and a key collaborator. He built on the equations originally developed by Arrhenius and Gibbs to capture the importance of the enzyme’s heat capacity to predict rates of enzyme-catalysed reactions. Together we have been testing how well MMRT is able to capture temperature response of enzyme, microbes, soil processes, leaf respiration and ecosystem response.
MMRT works very well – predicting a temperature optimum for enzyme activity without requiring denaturation. MMRT also allows determination of Tinf – the temperature at which the temperature sensitivity is maximal, i.e., when the rate of change in activity is maximal for a change in temperature.
Some key paper to date:
Schipper, L.A.; Hobbs, J.K.; Rutledge S.; Arcus, V.L. (2014) Thermodynamic theory explains the temperature optima of soil microbial processes and High Q10 Values at Low Temperatures. Global Change Biology. DOI: 10.1111/gcb.12596
Arcus, V.L.; Prentice, E.; Hobbs, J.K.; Mulholland, A.J.; Vander Kamp, M.W.; Pudney, C.R.; Parker, E.J.; Schipper, L.A. (2016) On the temperature dependence of enzyme-catalysed rates. Biochemistry. 55: 1681-1688. ACS Editors’ Choice
Hobbs, J.K.; Jiao, W.; Easter, A.D.; Parker, E.J.; Schipper, L.A.; Arcus, V.L. (2013) The Change in Heat Capacity for Enzyme Catalysis Determines the Temperature Dependence of Enzyme Catalysed Rates. ACS Chemical Biology. 8: 2388-2393.