Biosynthesis penicillin

Due to the importance of penicillins and cephalosporins, which certainly saved the lives of hundreds of millions of people, especially the mechanism of the penicillin biosynthesis was intensively investigated (24). Although total syntheses of penicillins are known now for more than 50 years, this reaction in which both rings of the penicillin structure are formed in one step is still impossible to reproduce for... 

Thioesterases of AC V synthetases differ from other thioesterases integrated in nonribosomal peptide synthetases in their direct association with an epimerase domain. A comparison of the primary sequences reveals significant differences to other NRPS thioesterases shown in Table 9. So the GXSXG motif may be involved in the control of tripeptide epimerization by selection of the isomer to be released. Finally, the data support the presence of LLL-AC V as an intermediate in penicillin biosynthesis. 

DJ Smith, AJ Earl, G Turner. The multifunctional peptide synthetase performing the first step of penicillin biosynthesis in Penicillium chrysogenum is a 421,073 dalton protein similar to Bacillus brevis peptide antibiotic synthetases. EMBO J 9 2743-2750, 1990. 

F Lara, R Del Carmen Mateos, G Vazquez, S Sanchez. Induction of penicillin biosynthesis by L-glutamate in Penicillium chrysogenum. Biochem Biophys Res Commun 105 172-178, 1982. 

W Kallow, H von Dohren, H Kleinkauf. Penicillin biosynthesis energy requirement for tripeptide precursor formation by delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase from Acremonium chrysogenum. Biochemistry 37 5947-5952, 1998. 

T Lendenfeld, D Ghali, M Wolschek, EM Kubicek-Pranz, CP Kubicek. Subcellular compartmentation of penicillin biosynthesis in Penicillium chrysogenum. The amino acid precursors are derived from the vacuole. J Biol Chem 268 665-671, 1993. 

The mechanism of penicillin biosynthesis from the Arnstein tripeptide, 8-(L-a-aminoadipoyl)-L-cysteinyl-D-valine (ACV), has been extensively studied and reviewed by many chemists. Most of the biosynthetic mechanisms have been ascertained by Baldwin and Bradley using an excellent enzymatic technique.55 However, the first step in the biosynthesis of penicillin, conversion of the Arnstein tripeptide to a cis-P-lactam intermediate, is still a fascinating mechanistic problem. Although Baldwin et al. recently proposed a mechanism involving an iron-bound thioaldehyde formation route via a Pummerer-type cyclization, the intermediate for this mechanism has not been identified. The mechanism of selective formation of the cw-P-lactam ring is still also unknown (Fig. 39).56 These types of biomimetic reactions have been chemically studied. An example of an unsuccessful intramolecular Pummerer cyclization of the sulfoxide involving a cysteine moiety under standard Pummerer conditions was reported by Wolfe et al.57 Although Kaneko reported the conversion of the very simple 3-phenylsulfinyl propionamide into a P-lactam with TMSOTf/triethylamine,58 a successful biomimetic synthesis of... 

Although cephalosporin C is divisable into a-aminoadipic acid, cysteine, and valine, the actual mechanism whereby Cephalosporium sp. incorporates the three amino acids into cephalosporin C has not been established, Arnstein and Morris isolated 8 (a-aminoadipyl) cysteinyl valine from mycelia of Penicillium chrysogenum and suggested that the tripeptide is a precursor in all penicillin biosynthesis.. This same tripeptide also appears to be found in the intracellular pool of Cephalosporium sp.- The final postulated step in the biosynthesis of penicillin is an acyl transfer reaction, or the production of 6-aminopeni-cillanic acid if precursor is not added. Cephalosporium sp. apparently do not produce sidechain amidases or acyl transferases, and no 7-ACA has been reported found in the fermentation. Thus, to obtain clinically useful antibiotics, chemical manipulation of cephalosporin C is necessary. Synthesis of many 7-acyl derivatives was possible once a practical cleavage reaction made available large amounts of 7-ACA from cephalosporin C. of these derivatives, sodium cephalothin was the first... 

Unlike primary metabolites, the genes that regulate the formation of the enzymes of seeondary metaboUte biosynthesis are often clustered. In several eases the loei of these genes have been determined. This has considerable sig-nifieanee in the control of secondary metabolite biosynthesis. The genes that eode for several important polyketide pathways such as those leading to the aflatoxins and the statins have been identified. Similar work has also been reported for penicillin biosynthesis and some non-ribosomal peptides as well as terpenoid pathways such as that leading to the gibberellins. 

Carbon atom 5 of the penicillins [as (198)] has been shown to derive from C-3 of cyst(e)ine [as (201)]. In feeding experiments with (2R, 3R)-[2,3- H2]cysteine, 2R, 3S)-[3- H]cysteine, and [3,3 - H2]cystine the fates of the hydrogen atoms originally present at C-3 of cysteine have been examined. As expected tritium label was to some extent lost from C-2 of cysteine. More importantly, retention of nearly one half of the tritium from [3,3 - H2]cystine indicated that hydrogen loss from C-3 was stereospecific. Further, high retention of tritium at C-5 of the penicillin G (199) derived from (2R, 3l )-[2,3- H2]cysteine and low retention in the experiment with (2R, 3S)-[3- H]cysteine demonstrates that it is the 3-pro-S hydrogen of cysteine which is lost in penicillin biosynthesis, and overall the transformation occurs with retention of configuration, as it does for valine. 

Me2- H6]Valine gave penieillin N (220) and penicillin V(219) with complete retention of deuterium, and thus intermediates of the type (224) are excluded from penicillin biosynthesis. In support (2S,3S)-[4,4,4- H3]valine (225) and (2S,3K)-[4,4,4- H3]valine each afforded exclusively trideuteriated penicillin N(220). ... 

In contrast, the penicillin biosynthesis genes in P. chrysogenum are considered to be expressed completely concomitantly. 

The enzymes involved in penicillin biosynthesis are distributed at different sites of the cell ACV-activity was found to be bound to vacuole membranes, IPN-synthase occurs dissolved in the cytoplasm and lAT-activity is microbody associated. 

Penaiva M A, Rowlands R T, Turner G (1998). The optimization of penicillin biosynthesis in fungi. TIBTECH 16 483-489. 

Brakhage A A, Sprote P, Ai-Abdaiiah Q, Gehrke A, Plattner H, Tuncher A (2004). Regulation of penicillin biosynthesis in filamentous fungi. Adv. Biochem. Eng. Biotechnol. 88 45-90. 

Newbert R W, Barton B, Greaves P, Harper J, Turner G (1997). Analysis of a commercially improved Penicillium chrysogenum strain series involvement of recombi-nogenic regions in amplification and deletion of the penicillin biosynthesis gene cluster. J. Ind. Microbiol. Biotechnol. 19 18-27. 

Brakhage A A, Browne P, Turner G (1994). Analysis of penicillin biosynthesis and the expression of penicillin biosynthesis genes of Aspergillus nidulans by targeted disruption of the acvA gene. Mol. Gen. Genet. 242 57-64. 

Matelova V, Brecka A, Matouskova J (1972) New method of intermittent feeding in penicillin biosynthesis. J Appl Microbiol 23 669-670... 

Aspergillus nidulans npeA locus consists of three contiguous genes required for penicillin biosynthesis, EMBOJ., 1990, 9, 279-287. 

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