Dihydrofolate

Dihydrofolate reductase (EC 1.5.1.3) is a key enzyme in the folate biosyn-thetic pathway. Information regarding key residues in the dihydrofolate-binding site ofMycobacterium aviumdihydrofolate reductase is lacking. On the basis of previous information, Asp31 and Leu32 were selected as resi-dues that are potentially important in interactions with dihydrofolate and antifolates (e.g. trimethoprim), respectively.

13p galaxyss3 19-03-2013 53 4   Download

Post-translational glycosylation is one of the most abundant forms of cova-lent protein modification in eukaryotic cells. It plays an important role in determining the properties of proteins, and stabilizes many proteins against thermal denaturation. Protein glycosylation may establish a surface micro-environment that resembles that of unglycosylated proteins in concentrated solutions of sugars and other polyols.

9p mobifone23 21-01-2013 43 4   Download

N5, N10 - metilen H4 folate Gliycine Serine 7,8 – Dihydrofolate Sự trao đổi của lipid và acid nucleic có rất ít mối liên quan trực tiếp, chúng chỉ liên quan gián tiếp thông qua trao đổi saccharide và protein. Một số dẫn xuất nucleoside diphosphate như cytidine diphosphate choline và cytidine disphosphate ethanolamine tham gia vào quá trình sinh tổng hợp phosphatid với vai trò chất cho gốc choline và ethanolamine.

5p conthancon 04-07-2011 109 10   Download

Tên chung quốc tế: Trimethoprim. Mã ATC: J01E A01. Loại thuốc: Kháng khuẩn. Dạng thuốc và hàm lượng: Viên nén 100 mg; 200 mg trimethoprim. Trimethoprim tiêm (dưới dạng lactat) 20 mg/ml. Dược lý và cơ chế tác dụng Trimethoprim có tác dụng kìm khuẩn, ức chế enzym dihydrofolate reductase của vi khuẩn. Trimethoprim chống lại tác nhân gây nhiễm khuẩn đường tiết niệu như E. coli, Proteus, Klebsiella, Enterobacter, Staphylococcus saprophyticus, Streptococcus faecalis và chống lại nhiều vi khuẩn dạng coli. ...

8p dududam 18-05-2011 80 11   Download

Trimethoprim Trimethoprim is a diaminopyrimidine, a structural analogue of the pteridine moiety of folic acid. Trimethoprim is a competitive inhibitor of dihydrofolate reductase; this enzyme is responsible for reduction of dihydrofolic acid to tetrahydrofolic acid—the essential final component in the folic acid synthesis pathway. Like that of the sulfonamides, the activity of trimethoprim is compromised in the presence of exogenous thymine or thymidine. Inhibition of Nucleic Acid Synthesis or Activity Numerous antibacterial compounds have disparate effects on nucleic acids.

7p colgate_colgate 21-12-2010 62 3   Download

Pemetrexed is a novel folate-directed antimetabolite. It is "multitargeted" in that it inhibits the activity of several enzymes, including thymidylate synthetase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase, thereby affecting the synthesis of both purine and pyrimidine nucleic acid precursors. To avoid significant toxicity to the normal tissues, patients receiving pemetrexed should also receive low-dose folate and vitamin B12 supplementation.

5p konheokonmummim 03-12-2010 69 4   Download