Biomaterial Database

omega- and (omega--1)-hydroxylation of fatty acids by frog liver microsomes. Substrate specificity and other properties. 1978

Y Miura, and H Hisaki, and N Ueta

Frog liver microsomes catalyzed the hydroxylation of various saturated fatty acids whose chain lengths were from 8 to 18 carbon atoms into the corresponding omega- and (omega--1)-hydroxy derivatives. In addition, small amounts of the dicarboxylic acids and (omega--1)-keto acids were also formed from all the fatty acids. The relative activity of the hydroxylase with the substrates was as follows: C13(100), C12(98), C14(88), C10(62), C16(34), C18(29), and C8(8). The percentage of omega-hydroxy derivative relative to the (omega--1)-isomer increased with increasing carbon chain length of the fatty acid substrate. Oleate, linoleate and linolenate were also tested and found to be at least as active their saturated analog (stearate). Both NADPH and O2 were required for hydroxylase activity. The apparent Km for NADPH was 3.7 . 10(-5) M, and NADH had very little effect. The apparent Km value for laurate was 1.5 . 10(-5) M. The hydroxylating system was about 50% inhibited by 10 mM KCN and 81% inhibited by CO at a CO : O2 ratio of 4.0. In contrast, NaN3 showed no effect on hydroxylation.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D005230	Fatty Acids, Nonesterified	FATTY ACIDS found in the plasma that are complexed with SERUM ALBUMIN for transport. These fatty acids are not in glycerol ester form.	Fatty Acids, Free,Free Fatty Acid,Free Fatty Acids,NEFA,Acid, Free Fatty,Acids, Free Fatty,Acids, Nonesterified Fatty,Fatty Acid, Free,Nonesterified Fatty Acids
D006899	Mixed Function Oxygenases	Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.	Hydroxylase,Hydroxylases,Mixed Function Oxidase,Mixed Function Oxygenase,Monooxygenase,Monooxygenases,Mixed Function Oxidases,Function Oxidase, Mixed,Function Oxygenase, Mixed,Oxidase, Mixed Function,Oxidases, Mixed Function,Oxygenase, Mixed Function,Oxygenases, Mixed Function
D006900	Hydroxylation	Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)	Hydroxylations
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
D001001	Anura	An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.	Bombina,Frogs and Toads,Salientia,Toad, Fire-Bellied,Toads and Frogs,Anuras,Fire-Bellied Toad,Fire-Bellied Toads,Salientias,Toad, Fire Bellied,Toads, Fire-Bellied
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities