title: In vivo transport of the intermediates of the penicillin biosynthetic pathway in tailored strains of Penicillium chrysogenum.
abstract: Penicillium chrysogenum npe10 (Deltapen; lacking the 56.8-kbp amplified region containing the penicillin gene cluster), complemented with one, two, or three penicillin biosynthetic genes, was used for in vivo studies on transport of benzylpenicillin intermediates. 6-Aminopenicillanic acid (6-APA) was taken up efficiently by P. chrysogenum npe10 unlike exogenous delta(L: -alpha-aminoadipyl)-L: -cysteinyl-D: -valine or isopenicillin N (IPN), which were not taken up or were taken up very poorly. Internalization of exogenous IPN and 6-APA inside peroxisomes was tested by quantifying their peroximal conversion into benzylpenicillin in strains containing only the penDE gene. Exogenous 6-APA was transformed efficiently into benzylpenicillin, whereas IPN was converted very poorly into benzylpenicillin due to its weak uptake. IPN was secreted to the culture medium. IPN secretion decreased when increasing levels of phenylacetic acid were added to the culture medium. The P. chrysogenum membrane permeability to exogenous benzylpenicillin was tested in the npe10 strain. Penicillin is absorbed by the cells by an unknown mechanism, but its intracellular concentration is kept low.
authors.affiliation: Instituto de Biotecnología (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006, León, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: García-Estrada
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Vaca
authors.forename: Mónica
authors.initials: M
authors.lastname: Lamas-Maceiras
authors.forename: Juan Francisco
authors.initials: JF
authors.lastname: Martín
mesh_terms: D001692:Biological Transport; D003470:Culture Media; D015536:Down-Regulation; D005800:Genes, Fungal; D005810:Multigene Family; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D010400:Penicillin G / Q000378:metabolism; D010406:Penicillins / Q000378:metabolism; D010408:Penicillium chrysogenum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D020675:Peroxisomes / Q000378:metabolism; D010648:Phenylacetates
chemical_list: D003470:Culture Media; D010406:Penicillins; D010648:Phenylacetates; D010397:Penicillanic Acid; C025136:phenylacetic acid; C006414:penicillin N; D010400:Penicillin G; C004408:aminopenicillanic acid