Biomaterial Database

Activities of D- and L-xyloascorbic acid and D- and L-araboascorbic acid as a cofactor for dopamine beta-hydroxylase reaction. 1997

E Suzuki, and T Kurata, and M Shibata, and M Mori, and N Arakawa

Department of Human Biological Studies, Ochanomizu University, Tokyo, Japan.

L-Xyloascorbic acid (L-xylo-AsA) and its three stereoisomers, D-xyloascorbic acid (D-xylo-AsA), L-araboascorbic acid (L-arabo-AsA) and D-araboascorbic acid (D-arabc-AsA), have been considered to show some differences in vitamin C activity. In this paper the effect of L-xylo-AsA, D-xylo-AsA, L-arabo-AsA and D-arabo-AsA on the activity of dopamine beta-hydroxylase was studied to clarify whether or not the structural specificities of these stereoisomers have different effects on enzyme activity. The maximum velocity (Vmax) of the hydroxylation and Km for ascorbic acid were calculated using double-reciprocal plotting. Vmax for L-xylo-AsA was estimated to be 201 nmol/min/mg protein and those of D-xylo-AsA, L-arabo-AsA and D-arabo-AsA were 157 nmol/min/mg protein, 112 nmol/min/mg protein and 194 nmol/min/mg protein, respectively. Km for L-xylo-AsA was 1.5 mM and those for D-xylo-AsA, L-arabo-AsA and D-arabo-AsA were 2.3 mM, 2.7 mM and 1.4 mM, respectively. The effect of D-arabo-AsA on the activity of dopamine beta-hydroxylase was almost the same as that of L-xylo-AsA, while D-xylo-AsA and L-arabo-AsA showed smaller effects. Our results suggest that the configuration at carbon 4 might be more important than that of the hydroxyl group at carbon 5 for the development of the activity as a cofactor for dopamine beta-hydroxylase reaction.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D004299	Dopamine beta-Hydroxylase		Dopamine beta-Monooxygenase,Dopamine beta Hydroxylase,Dopamine beta Monooxygenase,beta-Hydroxylase, Dopamine,beta-Monooxygenase, Dopamine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001205	Ascorbic Acid	A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.	Vitamin C,Ascorbic Acid, Monosodium Salt,Ferrous Ascorbate,Hybrin,L-Ascorbic Acid,Magnesium Ascorbate,Magnesium Ascorbicum,Magnesium di-L-Ascorbate,Magnorbin,Sodium Ascorbate,Acid, Ascorbic,Acid, L-Ascorbic,Ascorbate, Ferrous,Ascorbate, Magnesium,Ascorbate, Sodium,L Ascorbic Acid,Magnesium di L Ascorbate,di-L-Ascorbate, Magnesium
D013237	Stereoisomerism	The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer