Mathematical model of the aldol addition catalyzed by D-fructose-6-phosphate aldolase

U ovom radu je proučavana aldolna adicija formaldehida i propanala katalizirana enzimom D-fruktoza-6-fosfat aldolazom. Pri tome su korištene tri varijante enzima od kojih je za Var I provedena ekspresija u transformiranim stanicama bakterije Escherichia coli M15. Određena je kinetika aldolne adicije formaldehida i propanala u aldolni produkt 3-hidroksi-2-metilpropanal katalizirana sa tri varijante enzima D-fruktoza-6-fosfat aldolaze, te su na osnovu toga procijenjeni kinetički parametri reakcije. Ispitan je utjecaj različitih koncentracija varijanti enzima FSA na nastajanje aldola u promatranoj reakciji aldolne adicije u kotlastom i kotlastom reaktoru uz dotok supstrata. Ispitan je i utjecaj metanola te povratne reakcije raspada aldola na nastajanje aldolnog produkta te specifičnu aktivnost varijanti enzima FSA. Rezultati su pokazali da je Var I najbolji kandidat za provođenje reakcije po pitanju kinetičkih konstanti i postignute koncentracije aldolnog produkta.Examination of aldol addition of formaldehyde and propanal catalyzed by enzyme D-fructose-6-phosphate aldolase was carried out in this work. Three variants of enzyme were used, of which Var I was expressed in transformed cells of bacteria Escherichia coli M15 in this work. Kinetics of aldol addition of formaldehyde and propanal into aldol adduct 3-hydroxy-2-methylpropanal catalyzed with three variants of enzyme D-fructose-6-phosphate aldolase was determined, and kinetic parameters of reaction were estimated. The effect of different concentrations of FSA enzyme variants on aldol formation in observed reaction of aldol addition was tested in batch and fed-batch reactor. The influence of reverse aldol reaction and methanol presence on formation of aldol adduct and specific activity of FSA variants was tested. The overall results showed that Var I is the best candidate for carrying out examined reaction of aldol addition