... wereresidues Gly261 and Gly262. The replacement of Gly262 byAla resulted in an inactive enzyme. Substitution of Gly261by Ala resulted to an enzyme with lower stability and increased energy of activation. ... Bouriotis1,21Department of Biology, Division of Applied Biology and Biotechnology, University of Crete, Greece;2Institute of Molecular Biology and Biotechnology (IMBB), Enzyme Technology Division, and the3Institute ... moreactive.Determination of Ea and thermodynamic parameters for wild-type and mutant enzymes In order to elucidate the effect of mutations in terms of psychrophilic adaptation, we determined the energy of activation...