Enzymology of Biosynthesis

The second step in flavonoid synthesis is the isomerization of chalcone to flavanone, and the isomerase responsible has been isolated from parsley where 

One of the last steps in flavonoid synthesis is methylation and an 0-methyl-transferase for this has been purified 82-fold from cell suspiension cultures of parsley. It has a pH optimum of 9.7, requires Mg, and the molecular weight is ca. 48000. Unlike catechol methylase from animal tissues, it is not inhibited by p-chloromercuribenzoate or by iodoacetamide. Luteolin (27) and its 7-glucoside were the best substrates, giving chrysoeriol (28) and its 7-gluco-side respectively K values were 4.6 x 10 and 3.1 x 10 moll Erio-dictyol and caffeic acid were poor substrates (K values 1.2 x 10 and 1.6 X 10 moll , respectively) and the enzyme was quite spteciflc for catechols and only 0-methylated a m-hydroxy-group. 

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A Doller, A Haese, R Zocher. Molecular cloning of the amino acid activation domain of enniatin synthetase from Fusarium sambucinum. Symposium Enzymology of Biosynthesis of Natural Products, Abstract 66, Technische Universitat Berlin, September 22-25, 1996. 

Salicylic Acid.—It has recently been demonstrated (see last year s Report ) that whereas 6-methylsalicylic acid in both micro-organisms and higher plants is acetate-derived, salicylic add itself is formed in both groups of organisms by the shikimic add pathway. Further confirmation of this has come from Marshall and Ratledge, who have studied the enzymology of biosynthesis of salicylic acid in Mycobacterium smegmatis. These authors isolated the enzyme salicylate synthetase, which catalyses the last step (see Scheme 1) in synthesis of salicylic acid (1) from isochorismic add (2), formed in turn from chorismic (3) and shikimic adds (4). The enzyme has no cofactor requirements and converts (2) directly into (1). No evidence could be obtained for the presence in bacterial cultures of the possible intermediate 2,3-dihydroxy-2,3-dihydrobenzoic add. 

Niemetz R, Gross GG (2005), Enzymology of gallotannin and ellagitannin biosynthesis , Phytochemistry, 66, 2001-2011. 

VAN DER DEUDEN, R., THRELFALL, D.R., VERPOORTE, R WHITEHEAD, I.M., Regulation and enzymology of pentacyclic triterpenoid phytoalexin biosynthesis in cell suspension cultures of Tabemaemontana divaricata, Phytochemistry, 1989, 28, 2981-2988. 

The study of individual NRPS domain structures provides important information regarding the specificity and enzymology of individual steps in NRP biosynthesis. However, structural analysis of larger NRPS constructs is necessary to gain insight into aspects related to domain/domain interactions and the overall structure of the synthetase machinery. This information is particularly important for understanding the details of substrate trafficking and will assist efforts toward the rational manipulation of NRPSs. 

NRPSs are responsible for the biosynthesis of a wide range of structurally diverse natural products. Included in this large family of small molecules are several examples of clinically important therapeutics. The basic enzymology of these systems represents a fascinating example of complex multicomponent... 

Crosa JH, Walsh CT (2002) Genetics and Assembly Line Enzymology of Siderophore Biosynthesis in Bacteria. Microbiol Mol Biol Rev 66 223... 

Roberts, M. F. 1998. Production of alkaloids in plant cell culture. In Alkaloids. Biochemistry, Ecology, and Medicinal Applications (Roberts, M. F. and Wink, M., eds), pp. 159-197 and, Roberts, M. F. 1998. Enzymology of alkaloid biosynthesis. In Alkaloids. Biochemistry, Ecology, and Medicinal Applications (Roberts, M. F. and Wink, M., eds), pp. 109-146. New York - London Plenum Press. 

As a complement to the comprehensive Chapter on the biosynthesis of complex saccharides by Nikaido and Hassid in Vol. 26, where the products of biosynthesis were stressed, Kochetkov and Shibaev (Moscow) here emphasize the nucleotide sugar biosynthetic intermediates, themselves, in a detailed article on their chemistry and enzymology. 

Nakayama T. 2002. Enzymology of aurone biosynthesis. J Biosci Bioeng 94 487-491. 

Martin JF, Aparicio JF (2009) Enzymology of the polyenes pimaricin and candicidin biosynthesis. Methods Enzymol 459 215-242... 

MJ Bibb, S Biro, H Motamedi, JF Collins, CR Hutchinson. Analysis of the nucleotide sequence of the Streptomyces glaucescens tcml genes provides key information about the enzymology of polyketide biosynthesis. EMBO J 8 2727-2736, 1989. 

From a biogenetic standpoint, capsaicin is an acylated degraded phenylpropanoid. Both its aromatic and its acyl moiety are the result of unique metabolic processes that, though simple in principle, are still poorly characterized in terms of enzymology and regulation. Since vanillamine (23) is abundant in placental tissues of Capsicum, the only site of biosynthesis of capsaicinoids, the limiting factor for the synthesis of... 

Schneider G and Lindqvist Y (2001) Structural enzymology of biotin biosynthesis. EBBS Letters 495, 7-11. 

De Luca, V. (1993) Enzymology of indole alkaloid biosynthesis, in Methods in Plant Biochemistry (ed. P.J. Lea), Vol. 9. Academic Press, London, pp. 345-67. 

It should be emphasized here that there is a general lack of knowledge on the enzymology of betalain formation. This contrasts with the considerable progress that has been made in work on the biosynthesis of the analogous water-soluble flavonoids (99). The possible reactions involved in betalain biosynthesis have been deduced from feeding experiments with isotopically labeled dopa and tyrosine (115-119), which support the early suggestion of Wyler et al. (5) that dopa is the ultimate precursor for both the betalamic acid moiety in betaxanthins and betacyanins as well as the cyclodopa part in betacyanins. Furthermore,... 

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