Co-enzymes in the biochemistry

A cytosolic thyroid-hormone-binding protein (xCTBP), predominantly responsible for the major binding activity of T3 in the cytosol of Xenopus liver, has been shown to be identical to aldehyde dehydrogenase class 1 (ALDH1) [Yamauchi, K., Nakajima, J., Hayashi, H., Horiuchi, R. & Tata, J.R. (1999) J. Biol. Chem. 274, 8460–8469]. Within this paper we surveyed which signaling, and other, compounds affect the thyroid hormone binding activity and aldehyde dehydrogenase activity of recombinant Xenopus ALDH1 (xCTBP/xALDH1) while examining the relationship between these two activities....

8p research12 01-06-2013 37 3   Download

The role of coenzyme binding in regulating interflavin electron transfer in human cytochrome P450 reductase (CPR) has been studied using temperature-jump spectros-copy. Previous studies [Gutierrez, A., Paine, M., Wolf, C.R., Scrutton, N.S., & Roberts, G.C.K.Biochemistry (2002) 41,4626–4637] have shown that the observed rate, 1/s, of interflavin electron transfer (FADsq )FMNsq fi FADox)FMNhq) inCPRreduced at the two-electron level with NADPH is 55 ± 2 s )1 , whereas with dithionite-reduced enzyme the observed rate is 11 ± 0.

10p fptmusic 16-04-2013 31 2   Download

Apple flavor is characterized by combinations of ester compounds, which increase markedly during fruit ripening. The final step in ester biosynthesis is catalyzed by alcohol acyl transferases (AATs) that use coenzyme A (CoA) donors together with alcohol acceptors as substrates. The gene MpAAT1, which produces a predicted protein containing features of other plant acyl transferases, was isolated fromMalus pumila(cv. Royal Gala). TheMpAAT1gene is expressed in leaves, flowers and fruit of apple.

13p fptmusic 11-04-2013 36 1   Download

The functional activities of proteins are closely related to their molecular structure and understanding their structure–function relationships remains one of the intriguing problems of molecular biology. We investigated struc-tural changes in 17b-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus(17b-HSDcl) induced by pH, temperature, salt, urea, guanidine hydrochloride, and coenzyme NADPH binding.

11p inspiron33 25-03-2013 39 3   Download

Inhibition of the mitochondrial adenine nucleotide translocator (ANT) by long-chain acyl-CoA esters has been proposed to contribute to cellular dys-function in obesity and type 2 diabetes by increasing formation of reactive oxygen species and adenosine via effects on the coenzyme Q redox state, mitochondrial membrane potential (Dw) and cytosolic ATP concentrations.

15p inspiron33 23-03-2013 53 3   Download

The biosynthesis of lovastatin inAspergillus terreusrequires two mega-synthases. The lovastatin nonaketide synthase, LovB, synthesizes the inter-mediate dihydromonacolin L using nine malonyl-coenzyme A molecules, and is a reducing, iterative type I polyketide synthase.

11p galaxyss3 19-03-2013 31 3   Download

The X-ray structure of the diol dehydratase–adeninylpentylcobalamin com-plex revealed that the adenine moiety of adenosylcobalamin is anchored in the adenine-binding pocket of the enzyme by hydrogen bonding of N3 with the side chain OH group of Sera224, and of 6-NH2, N1 and N7 with main chain amide groups of other residues.

13p vinaphone15 28-02-2013 51 1   Download

Flavin-dependent thymidylate synthases (FDTS) catalyze the production of dTMP from dUMP and N 5 ,N 10 -methylene-5,6,7,8-tetrahydrofolate (CH2H4 folate). In contrast to human and other classical thymidylate synth-ases, the activity of FDTS depends on a FAD coenzyme, and its catalytic mechanism is very different.

10p viettel02 22-02-2013 37 1   Download

We summarize the currently available information regarding the state of ionization and tautomerization of the 4¢-aminopyrimidine ring of the thia-mine diphosphate on enzymes requiring this coenzyme. This coenzyme forms a series of covalent intermediates with its substrates as an electro-philic catalyst, and the coenzyme itself also carries out intramolecular pro-ton transfers, which is virtually unprecedented in coenzyme chemistry.

15p viettel02 22-02-2013 46 2   Download

The vitamins are a chemically disparate group of compounds whose only common feature is that they are dietary essentials that are required in small amounts for the normal functioning of the body and maintenance of metabolic integrity.Metabolically, they have diverse functions, such as coenzymes, hormones, antioxidants, mediators of cell signaling, and regulators of cell and tissue growth and differentiation.

511p cronus75 14-01-2013 62 15   Download