It is shown by analysis of a cyclic enzymatic network that the presence zero net flux/current cycles impose strong thermodynamic constraints on values kinetic parameters. Thermodynamic carried out for four-node pyramidal reaction involving conversion 7,8-­dihydrofolate (H2F) and NADPH in H+ to 5,6,7,8-­tetrahydrofolate (H4F) NADP+ catalyzed universal enzyme dihydrofolate reductase (DHFR). The c...

background: trastuzumab (herceptin) is a humanized monoclonal antibody (mab) which is used for specific treatment of metastatic breast cancer in patients with overexpression of her2/neu receptor. in this study, we have attempted to develop a biosimilar version of trastuzumab mab. methods: according to in silico studies, the heavy and light chains of trastuzumab mab were designed and constructed...

The implication of dihydrofolate reductase and dihydropteroate synthetase gene mutations in modification of Plasmodium falciparum characteristics Abstract Background: The Plasmodium falciparum dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) are enzymes of central importance in parasite metabolism. The dhfr and dhps gene mutations are known to be associated with sulphadoxine...

A gene encoding a bifunctional homodimeric dihydrofolate reductase-thymidylate synthase (DHFR-TS) was constructed by destroying the stop codon of Escherichia coli dihydrofolate reductase (DHFR) and joining the coding sequences of the monofunctional enzymes by a five amino acid linker. The protein was designed to mimic features of active site proximity and electrostatics in the protozoan DHFR-TS...

We have observed that rodent cell lines (mouse, hamster) contain approximately 10 times the levels of dihydrofolate reductase as human cell lines, yet the sensitivity to methotrexate (ED(50)), the folate antagonist that targets this enzyme, is similar. Our previous studies showed that dihydrofolate reductase protein levels increased after methotrexate exposure, and we proposed that this increas...

Dihydrofolalate reductase (DHFR) inhibitors are of significant interest as potential tool against parasites and other microbial infections. Dihydrofolate reductase is a ubiquitous enzyme present in almost all eukaryotic and prokaryotic cells and has potential importance in biochemistry and medicinal chemistry. It catalyses the various biochemical reactions are of vital importance, inhibition of...

Dihydropteroate synthase (DHPS) can metabolise sulfa drugs into sulfa-dihydropteroate (sulfa-DHP), which inhibits cell growth through competition with dihydrofolate (DHF), possibly indicating dihydrofolate reductase (DHFR) as the target of sulfa-DHP. The effect of over-production of DHFR on sulfa-DHP resistance was examined in Saccharomyces cerevisiae using a strain that requires DHF for growth...

background: protozoa related to trypanosome family including leishmania , synthesize enzymes to escape from drug therapy. one of them is ptr1 that its enzymatic activity is similar to dihydrofolate reductase (dhfr). dihydrofolate reductase - thymidylate synthase has a major role in dna synthesis, if it is inhibited, the result would be the death of parasite. since ptr1 activity is similar to dh...

In a previous report it was shown that mammalian ribosomes were capable of initiating translation at a non-AUG triplet when the initiation codon of mouse dihydrofolate reductase (dhfr) was mutated to ACG (Peabody, D.S. (1987) J. Biol. Chem. 262, 11847-11851). In order to assess the capacity of the mammalian translation apparatus to initiate at other non-AUG triplets, the initiator AUG of dihydr...