- Drug Week October 2nd, 2009
A new study, 'Enzyme stabilization by domain insertion into a thernlophilic protein,' is now available. "Insufficient kinetic stability of exoinulinase (EI) restricts its application in many areas including enzymatic transformation of inulin for production of ultra-high fructose syrup and oligofructan, as well as fermentation of inulin into bioethanol. The conventional method for enzyme stabilization involves mutagenesis and therefore risks alteration of an enzyme's desired properties, such as activity," scientists in the United States report.
"Here, we report a novel method for stabilization of EI without any modification of its primary sequence. Our method employs domain insertion of an entire EI domain into a thermophilic scaffold protein. Insertion of EI into a loop of a thermophilic maltodextrin-binding protein from Pyrococcus furiosus (PfMBP) resulted in improvement of kinetic stability (the duration over which an enzyme remains active) at 37 degrees C without any compromise in EI activity," wrote C.S. Kim and colleagues, New York University.
The researchers concluded: "Our analysis suggests that the improved kinetic stability at 37 degrees C might originate from a raised kinetic barrier for irreversible conversion of unfolded intermediates to completely inactivated species, rather than an increased energy difference between the folded and unfolded forms."
Kim and colleagues published their study in Protein Engineering, Design & Selection (Enzyme stabilization by domain insertion into a thermophilic protein. Protein Engineering, Design & Selection, 2009;22(10):615-23).
For additional information, contact C.S. Kim, Polytechnic Institute of New York University, Othmer-lacobs Dept. of Chemical and Biological Engineering, 6 MetroTech Center, Brooklyn, NY 11201 USA.
The publisher's contact infornlation for the journal Protein Engineering, Design & Selection is: Oxford University Press, Great Clarendon St., Oxford OX2 6DP, England.