Distribution in microorganisms

Glutamic acid dehydrogenase is widely distributed in microorganisms and higher plants as a catalyst in the synthesis of L-glutamic acid from a-ketoglutaric acid and free ammonia. Transaminase is contained in a wide variety of microorganisms. 

Studies on microbial RNases began in 1924 when Noguchi found ribonucleic acid degrading enzymes in Takadiastase (134). Since then extensive studies have been carried out on RNA degrading enzymes. It is rather surprising that guanyloribonuclease so widely distributed in microorganisms was found only in 1957. This is because earlier studies did not consider base specificity. Even quite recently studies on nucleases or ribonucleases do not consider base specificity or do not separate nuclease mixtures from each other thus, information available on microbial RNases is still scant. 

Guanyloribonucleases are, as shown in Table XII, widely distributed in microorganisms, especially in fungi and streptomyces. These guanyloribonucleases may exhibit different fine relative specificity. Indeed the action of RNase T2 and guanyloribonucleases of streptomyces or actin-omyces on minor components in tRNA such as methylated guanylyl bonds or on chemically modified guanylyl bonds has been reported to be different (136-139). Further studies on such fine relative specificity are required. 

The enzymes are widely distributed in microorganisms, plants, and animals. " Three Mo-MPT enzymes have been found in mammals (1) xanthine dehydrogenase see Dehydrogenase) has many, varied roles in purine catabolism, drug metabolism, and oxidative stress response, (2) aldehyde oxidase is important in drug metabolism and the synthesis of retinoic acid from retinal, and (3) sulfite oxidase plays a cmcial role in the detoxification of sulfite produced in the degradation of cysteine and methionine. Genetic Mo-MPT deficiency in... 

CjHiiNsOj, Mr 237.22. The (l J ,2 S) form (L-erythro form) form ale yellow cryst., mp. 250-280 C (decomp.), [a]o-66 (0.1 m HCI), pK, 2.23, pK 2 7.89. In alkaline solution B. shows blue fluorescence. It is widely distributed in microorganisms, insects (e.g. in royaI jelly of queen bees), algae, amphibians, and mammals and is also found in urine. In metabolism tet-rahydro-B. acts as a cofactor for phenylalanine 4-monooxygenase (EC 1.14.16.1). B. is a growth factor for insects. The (l /, 2 /f) form (D-threo form) known as dictyopterin melts at >300 C and has pK , 2.20, pKa2 7.92. It occurs in the slime mold Dictyostelium discoideum. The biosynthesis starts from guanosine triphosphate. 

Rhizopus pepsin belongs to the aspartyl protease family, whose members are distributed in microorganisms, plants, and animals. This protease class cleaves peptide bonds on the N-terminal side of Phe or Tyr. 

The biocatalytic counterpart for the stereoselective reductirai of alkenes is catalyzed by flavin-dependent ene-reductases, " EC 1.3.1.31], which are members of the old yellow enzyme family (OYE, Scheme 2.134) [968,969], first described in the 1930s [970]. These enzymes are widely distributed in microorganisms and in plants. Some of them occur in well-defined pathways, e.g., in the biosynthesis of fatty acids and secondary metabolites, such as morphine [971] and jasmonic acid [972]. Others are involved in the detoxification of xenobiotics [973], such as nitro esters [974] and nitro-aromatics [975] like trinitrotoluene (TNT) [976]. 

Invertase has been found widely distributed in microorganisms, plants, and animals, The best-studied enzymes are those of yeast and other fungi. In higher animals invertase is produced only in the intestinal mucosa and acts only as a digestive enzyme. 

Transaminases are widely distributed in microorganisms, plant, and animal tissues (see reviews ). The type reaction catalyzed is the following ... 

Enzymes capable of interconverting d- and L-amino acid isomers are widely distributed in microorganisms. Racemases have been reported for... 

An enzyme, termed desoxyribose phosphate aldolase, - has been found widely distributed in microorganisms and animal tissues. The enzyme catalyzes the following reversible reaction ... 

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