AMP-PCP

L-serine-AMP. The condensation domain of EntF then catalyzes amide bond formation between each DHB-ArCP unit 79 and an L-serine-PCP molecule 80a to form 77a [107], Subsequently, the terminal thioesterase of EntF catalyzes the stepwise ester bond formation between each of the three tethered /V-(2,3-dihydrox-ybenzoyl) L-serine moieties (77a, 81, 82) as they are biosynthesized, as well as the cyclization and release of the final 12-membered trilactone 64 [108] (Fig. 13). 

AMPs was carried out using a C18 column, whereas opiates, PCP, cocaine, and BEG were separated on a PEP column. This is an example of a good analytical method that needs a time-consuming sample preparation and two chromatographic runs for the achievement of the best performances [115]. 

Based on the paradigm of NRPS-catalyzed reactions, we proposed a mechanism for the biosynthesis of the tricarballylic esters of fumonisins (Figure 5). The first step is the ATP-dependent activation of a tricarboxylate substrate by FumlOp to form an acyl-AMP, which is subsequently transferred to the PCP domain of Fuml4p. The exact substrate for FumlOp is not known, but is likely to be an intermediate of the tricaroxylatic acid cycle 17). The data obtained from the FUM7 deletion mutant suggested that the substrate of FumlOp could be a... 

AMP, amphetamines BAR, barbiturates BZO, benzodiazepines THC, cannabinoids COC, cocaine melaboiite MTD, methadone OPi, opiates PCP, phencyciidine TCA, tricyciic antidepressants. 

Nonribosomal peptide synthesis means that the peptide is not produced by the tRNA-mRNA mechanism described in Chapter 28, Section 28.6. Each amino acid found in 224 is directly selected for incorporation into the growing peptide chain by one of the domains of surfactin synthetase, shown with the pendant SH groups. Substrate activation occurs after binding the amino acid, and the enzyme catalyzes the formation of an aminoacyl adenylate intermediate using Mg2+-ATP and release of a cofactor. Subsequently, the amino acid-O-AMP oxoester is converted into a thioester by a nucleophilic attack of the free thiol-bound cofactor of an adjacent PCP domain. (Note that ATP is adenosine triphosphate and AMP is adenosine monophosphate see Chapter 28, Section 28.5.)... 

A minimal NRPS module consists of an adenylation domain (A), condensation domain (C) and a peptidyl-carrier protein (PCP). In the first instance, the substrate-specific adenylation domain activates the carboxyl region of the amino acid with ATP, forming the mixed acyl-phosphoric acid anhydride with AMP, followed by loading onto the phosphopanthetheine moiety of the PCP. The condensation domain subsequently catalyses the nucleophific attack of the amino group of the previously activated amino acid, to the carbonyl of the tethered acyl group from the previous module [38, 39]. This results in the formation of a new peptide bond between the two units (Fig. 1.15). 

THC, ll-nor-A-9-tetrahydrocannabinol-9-carboxyllc acid PCP, Phencyclidine BZE, benzoylecgonine BARB, barbiturates AMP, amphetamines LSD, lysergic acid diethylamide. 

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