Structure-activity correlationship and folding of recombinant Escherichia coli dihydro folate reductase (DHFR) enzyme through biochemical and biophysical approaches

Abstract

The design of any antagonist or inhibitor for any enzyme requires the knowledge of structurefunction relationship of the protein and the optimum conformational states for maximum and minimum activities. Furthermore, designing of the inhibitors or drugs against an enzyme becomes easier if there is information available about various well characterized intermediate conformation of the molecule. In vivo folding pathway of any recombinant protein is an important parameter for understanding its ability to fold by itself inside the cell, which always dictates the downstream processing for the purification. In the present manuscript we have discussed about the in vivo and in vitro folding, and structure-function relationship of Dihydrofolate reductase enzyme. This is an important enzyme involved in the cell growth and hence inhibition or inactivation of the enzyme may reduce the cell growth. It was observed that the equilibrium unfolding transition of DHFR proceeds through the formation of intermediates having higher exposed surface hydrophobicity, unchanged enzymatic activity and minimum changes in the secondary structural elements. Because of enhanced surface hydrophobicity, and unchanged enzymatic activity, these intermediates could be a nice target for designing drugs against DHFR.

Correlation study between DHFR enzyme and some biochemical parameters in diabetic type II patients

“…Dihydrofolatereductase (DHFR; 5,6,7,8-tetrahydro-folate : NADP+ oxidoreductase) (a 24 kDa protein) catalyzes the NADPH-dependent reduction of dihydrofolate (H 2 folate) or folic acid to tetrahydrofolate (H 4 folate) and is considered to be a key enzyme in folate metabolism [1]. H 2 folate is the product of thymidylate synthetase and must be recycled to H 4 folate in order to be incorporated into tetrahydrofolate metabolic pool.…”

“…Its binding to methotrexate depends on its con-formation, so it is very necessary that it should be pre-sent in its correctly folded form [1].…”