1
|
Sanhueza C, Araos J, Naranjo L, Villalobos R, Westermeier F, Salomon C, Beltrán AR, Ramírez MA, Gutiérrez J, Pardo F, Leiva A, Sobrevia L. Modulation of intracellular pH in human ovarian cancer. Curr Mol Med 2016; 16:23-32. [PMID: 26695697 DOI: 10.2174/1566524016666151222143437] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 10/29/2015] [Accepted: 12/18/2015] [Indexed: 11/22/2022]
Abstract
To sustain tumor growth, the cancer cells need to adapt to low levels of oxygen (i.e., hypoxia) in the tumor tissue and to the tumor-associated acidic microenvironment. In this phenomenon, the activation of the sodium/proton exchanger 1 (NHE1) at the plasma membrane and the hypoxia-inducible factor (HIF) are critical for the control of the intracellular pH (pHi) and for hypoxia adaptation, respectively. Interestingly, both of these mechanisms end in sustaining cancer cell proliferation. However, regulatory mechanisms of pHi in human ovary tissue and in malignant ascites are unknown. Additionally, a potential role of NHE1 in the modulation of H(+) efflux in human ovarian cancer cells is unknown. In this review, we discussed the characteristics of tumor microenvironment of primary human ovarian tumors and tumor ascites, in terms of pHi regulatory mechanisms and oxygen level. The findings described in the literature suggest that NHE1 may likely play a role in pHi regulation and cell proliferation in human ovarian cancer, potentially involving HIF2α activation. Since ovarian cancer is the fifth cause of prevalence of women cancer in Chile and is usually of late diagnosis, i.e., when the disease jeopardizes peritoneal cavity and other organs, resulting in reduced patient survival, new efforts are required to improve patient-life span and for a better understanding of the pathophysiology of the disease. The potential advantage of the use of amiloride and amiloride-derivatives for cancer treatment in terms of NHE1 expression and activity is also discussed as a therapeutic approach in human ovarian cancer.
Collapse
Affiliation(s)
- C Sanhueza
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, P.O. Box 114-D, Santiago 8330024, Chile.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Glanville J, D'Angelo S, Khan TA, Reddy ST, Naranjo L, Ferrara F, Bradbury ARM. Deep sequencing in library selection projects: what insight does it bring? Curr Opin Struct Biol 2016; 33:146-60. [PMID: 26451649 DOI: 10.1016/j.sbi.2015.09.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/19/2015] [Accepted: 09/17/2015] [Indexed: 11/17/2022]
Abstract
High throughput sequencing is poised to change all aspects of the way antibodies and other binders are discovered and engineered. Millions of available sequence reads provide an unprecedented sampling depth able to guide the design and construction of effective, high quality naïve libraries containing tens of billions of unique molecules. Furthermore, during selections, high throughput sequencing enables quantitative tracing of enriched clones and position-specific guidance to amino acid variation under positive selection during antibody engineering. Successful application of the technologies relies on specific PCR reagent design, correct sequencing platform selection, and effective use of computational tools and statistical measures to remove error, identify antibodies, estimate diversity, and extract signatures of selection from the clone down to individual structural positions. Here we review these considerations and discuss some of the remaining challenges to the widespread adoption of the technology.
Collapse
Affiliation(s)
- J Glanville
- Program in Computational and Systems Immunology, Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Stanford, CA, USA
| | - S D'Angelo
- University of New Mexico Comprehensive Cancer Center, and Division of Molecular Medicine, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - T A Khan
- ETH Zurich, Department of Biosystems Science and Engineering, Basel, Switzerland
| | - S T Reddy
- ETH Zurich, Department of Biosystems Science and Engineering, Basel, Switzerland
| | - L Naranjo
- Bioscience division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - F Ferrara
- University of New Mexico Comprehensive Cancer Center, and Division of Molecular Medicine, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - A R M Bradbury
- Bioscience division, Los Alamos National Laboratory, Los Alamos, NM, USA.
| |
Collapse
|
3
|
Sanhueza C, Araos J, Naranjo L, Sáez T, Silva L, Salsoso R, Pardo F, Leiva A, Cuello MA, Cornejo M, Ramírez MA, Sobrevia L. NHE1 PROMOTE CELL PROLIFERATION IN OVARIAN CANCER: A ROLE OF HYPOXIA-INDUCIBLE FACTORS.: IGCS-0038 06. Ovarian Cancer. Int J Gynecol Cancer 2015. [DOI: 10.1136/00009577-201505001-00043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
|
4
|
Sobrevia L, Sáez T, Salsoso R, Silva L, Villalobos R, Araos J, Naranjo L, Guzmán-Gutiérrez E, Gutiérrez J, Sanhueza C, Pardo F, Leiva A. Insulin restores L-arginine and adenosine transport requiring adenosine receptors espression in human fetoplacentaL endothelium from gestational diabetes mellitus. Placenta 2015. [DOI: 10.1016/j.placenta.2015.01.400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
|
6
|
|
7
|
Uribe‐Alvarez C, Ayala M, Perezgasga L, Naranjo L, Urbina H, Vazquez‐Duhalt R. First evidence of mineralization of petroleum asphaltenes by a strain of Neosartorya fischeri. Microb Biotechnol 2011; 4:663-72. [PMID: 21624102 PMCID: PMC3819015 DOI: 10.1111/j.1751-7915.2011.00269.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 04/03/2011] [Accepted: 04/04/2011] [Indexed: 11/30/2022] Open
Abstract
A fungal strain isolated from a microbial consortium growing in a natural asphalt lake is able to grow in purified asphaltenes as the only source of carbon and energy. The asphaltenes were rigorously purified in order to avoid contamination from other petroleum fractions. In addition, most of petroporphyrins were removed. The 18S rRNA and β-tubulin genomic sequences, as well as some morphologic characteristics, indicate that the isolate is Neosartorya fischeri. After 11 weeks of growth, the fungus is able to metabolize 15.5% of the asphaltenic carbon, including 13.2% transformed to CO(2) . In a medium containing asphaltenes as the sole source of carbon and energy, the fungal isolate produces extracellular laccase activity, which is not detected when the fungus grow in a rich medium. The results obtained in this work clearly demonstrate that there are microorganisms able to metabolize and mineralize asphaltenes, which is considered the most recalcitrant petroleum fraction.
Collapse
Affiliation(s)
- Cristina Uribe‐Alvarez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
| | - Marcela Ayala
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
| | - Lucia Perezgasga
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
| | - Leopoldo Naranjo
- Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas 1080, Venezuela
| | - Héctor Urbina
- Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas 1080, Venezuela
| | - Rafael Vazquez‐Duhalt
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62250 México
| |
Collapse
|
8
|
Sena L, Rojas D, Montiel E, González H, Moret J, Naranjo L. A strategy to obtain axenic cultures of Arthrospira spp. cyanobacteria. World J Microbiol Biotechnol 2011; 27:1045-1053. [PMID: 21625652 PMCID: PMC3079091 DOI: 10.1007/s11274-010-0549-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2009] [Accepted: 08/20/2010] [Indexed: 11/26/2022]
Abstract
A strategy to obtain axenic cultures of the cyanobacterium Arthrospira sp. ('platensis') Lefevre 1963/M-132-1 strain, consisting of a series of physical and chemical procedures, and the application of an optimized pool of antibiotics, is described in this paper. This strategy, which is an inexpensive and fast way to obtain axenic cultures, can be applied to Arthrospira spp. from culture collections or samples from their natural habitats to eliminate a wide spectrum of contaminants. A high alkaline treatment (pH 12, using KOH) of 72 h is a determinant initial procedure applied to eliminate protozoa and Microcystis sp. Bacteria were eliminated by an optimal antibiotic pool treatment, and Chroococcus sp. residuals were discarded by serial dilution. Optimal concentrations of the antibiotics composing the pool were obtained by a 2(4) factorial central composite rotatable design (CCRD) and Response Surface Methodology (RSM), resulting in: ampicillin 61.6 μg/ml, penicillin 85.8 μg/ml, cefoxitin 76.9 μg/ml, and meropenem 38.9 μg/ml. The results also indicate that cefoxitin was the most effective antibiotic of this pool. After obtaining the axenic culture, identification of Lefevre 1963/M-132-1 strain was performed using amplification and sequencing of the ITS region (including part of 16S rRNA, tRNA Ile, ITS, tRNA Ala and part of 23S rRNA region) and fatty acid composition data. Data base comparison revealed that Lefevre strain is closely related to A. platensis species (99% identity), while fatty acid composition data suggested A. maxima. These seemingly contradictory results are discussed.
Collapse
Affiliation(s)
- Lucia Sena
- Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas, 1080 Venezuela
| | - Diego Rojas
- Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas, 1080 Venezuela
| | - Edie Montiel
- Grupo de Optimización Agrícola (GOA), Instituto de Zoología y Ecología Tropical (IZET), Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Héctor González
- Grupo de Optimización Agrícola (GOA), Instituto de Zoología y Ecología Tropical (IZET), Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Josnell Moret
- Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas, 1080 Venezuela
| | - Leopoldo Naranjo
- Dirección de Área de Energía y Ambiente, Fundación Instituto de Estudios Avanzados (IDEA), Sartenejas, Caracas, 1080 Venezuela
| |
Collapse
|
9
|
Teves F, Lamas-Maceiras M, García-Estrada C, Casqueiro J, Naranjo L, Ullán RV, Scervino JM, Wu X, Velasco-Conde T, Martín JF. Transcriptional upregulation of four genes of the lysine biosynthetic pathway by homocitrate accumulation in Penicillium chrysogenum: homocitrate as a sensor of lysine-pathway distress. Microbiology (Reading) 2009; 155:3881-3892. [PMID: 19696106 DOI: 10.1099/mic.0.031005-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The lysine biosynthetic pathway has to supply large amounts of alpha-aminoadipic acid for penicillin biosynthesis in Penicillium chrysogenum. In this study, we have characterized the P. chrysogenum L2 mutant, a lysine auxotroph that shows highly increased expression of several lysine biosynthesis genes (lys1, lys2, lys3, lys7). The L2 mutant was found to be deficient in homoaconitase activity since it was complemented by the Aspergillus nidulans lysF gene. We have cloned a gene (named lys3) that complements the L2 mutation by transformation with a P. chrysogenum genomic library, constructed in an autonomous replicating plasmid. The lys3-encoded protein showed high identity to homoaconitases. In addition, we cloned the mutant lys3 allele from the L2 strain that showed a G(1534) to A(1534) point mutation resulting in a Gly(495) to Asp(495) substitution. This mutation is located in a highly conserved region adjacent to two of the three cysteine residues that act as ligands to bind the iron-sulfur cluster required for homoaconitase activity. The L2 mutant accumulates homocitrate. Deletion of the lys1 gene (homocitrate synthase) in the L2 strain prevented homocitrate accumulation and reverted expression levels of the four lysine biosynthesis genes tested to those of the parental prototrophic strain. Homocitrate accumulation seems to act as a sensor of lysine-pathway distress, triggering overexpression of four of the lysine biosynthesis genes.
Collapse
Affiliation(s)
- Franco Teves
- Área de Microbiología, Departamento de Biología Molecular, Facultad de CC. Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 Leon, Spain
| | - Mónica Lamas-Maceiras
- Área de Microbiología, Departamento de Biología Molecular, Facultad de CC. Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 Leon, Spain
| | - Carlos García-Estrada
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain
| | - Javier Casqueiro
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain.,Área de Microbiología, Departamento de Biología Molecular, Facultad de CC. Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 Leon, Spain
| | - Leopoldo Naranjo
- Área de Microbiología, Departamento de Biología Molecular, Facultad de CC. Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 Leon, Spain
| | - Ricardo V Ullán
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain
| | - José-Martín Scervino
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain
| | - Xiaobin Wu
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain
| | - Tania Velasco-Conde
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain
| | - Juan F Martín
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av. Real, 1, 24006 León, Spain.,Área de Microbiología, Departamento de Biología Molecular, Facultad de CC. Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 Leon, Spain
| |
Collapse
|
10
|
Noya BAD, Ruiz R, Diaz Z, Colmenares C, Zavala R, Mauriello L, Surez J, Torres J, Naranjo L, Castro J, Marques J, Mendoza I, Ossenkopp J, Noya O. Large Outbreak of Orally-Acquired Acute Chagas’ Disease, in a Publlc School of Caracas, Venezuela. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
11
|
de Sisto A, Fusella E, Urbina H, Leyn V, Naranjo L. Molecular characterization of bacteria isolated from waste electrical transformer oil. ACTA ACUST UNITED AC 2008. [DOI: 10.3103/s0027131408020168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
12
|
Urbina H, Reyes A, Fusella E, Gonzalez M, Leon V, Naranjo L. Pycnoporus sanguineus IDEA, a laccase-overproducing fungi with high potential in partial enzymatic conversion (PEC-Technology) of Venezuelan extra-heavy crude oil. J Biotechnol 2007. [DOI: 10.1016/j.jbiotec.2007.07.163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
13
|
Naranjo L, Lamas-Maceiras M, Ullán RV, Campoy S, Teijeira F, Casqueiro J, Martín JF. Characterization of the oat1 gene of Penicillium chrysogenum encoding an omega-aminotransferase: induction by L-lysine, L-ornithine and L-arginine and repression by ammonium. Mol Genet Genomics 2005; 274:283-94. [PMID: 16163487 DOI: 10.1007/s00438-005-0019-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Accepted: 06/11/2005] [Indexed: 11/29/2022]
Abstract
The Penicillium chrysogenum oat1 gene, which encodes a class III omega-aminotransferase, was cloned and characterized. This enzyme converts lysine into 2-aminoadipic semialdehyde, and plays an important role in the biosynthesis of 2-aminoadipic acid, a precursor of penicillin and other beta-lactam antibiotics. The enzyme is related to ornithine-5-aminotransferases and to the lysine-6-aminotransferases encoded by the lat genes found in bacterial cephamycin gene clusters. Expression of oat1 is induced by lysine, ornithine and arginine, and repressed by ammonium ions. AreA-binding GATA and GATT sequences involved in regulation by ammonium, and an 8-bp direct repeat associated with arginine induction in Emericella (Aspergillus nidulans and Saccharomyces cerevisiae, were found in the oat1 promoter region. Deletion of the oat1 gene resulted in the loss of omega-aminotransferase activity. The null mutants were unable to grow on ornithine or arginine as sole nitrogen sources and showed reduced growth on lysine. Complementation of the null mutant with the oat1 gene restored normal levels of omega-aminotransferase activity and the ability to grow on ornithine, arginine and lysine. The role of the oat1 gene in the biosynthesis of 2-aminoadipic acid is discussed.
Collapse
Affiliation(s)
- Leopoldo Naranjo
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Spain
| | | | | | | | | | | | | |
Collapse
|
14
|
Valmaseda EMMD, Campoy S, Naranjo L, Casqueiro J, Martín JF. Lysine is catabolized to 2-aminoadipic acid in Penicillium chrysogenum by an omega-aminotransferase and to saccharopine by a lysine 2-ketoglutarate reductase. Characterization of the omega-aminotransferase. Mol Genet Genomics 2005; 274:272-82. [PMID: 16049680 DOI: 10.1007/s00438-005-0018-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Accepted: 05/05/2005] [Indexed: 10/25/2022]
Abstract
The biosynthesis and catabolism of lysine in Penicillium chrysogenum is of great interest because these pathways provide 2-aminoadipic acid, a precursor of the tripeptide delta-L-2-aminoadipyl-L-cysteinyl-D-valine that is an intermediate in penicillin biosynthesis. In vivo conversion of labelled L-lysine into two different intermediates was demonstrated by HPLC analysis of the intracellular amino acid pool. L-lysine is catabolized to 2-aminoadipic acid by an omega-aminotransferase and to saccharopine by a lysine-2-ketoglutarate reductase. In lysine-containing medium both activities were expressed at high levels, but the omega-aminotransferase activity, in particular, decreased sharply when ammonium was used as the nitrogen source. The omega-aminotransferase was partially purified, and found to accept L-lysine, L-ornithine and, to a lesser extent, N-acetyl-L-lysine as amino-group donors. 2-Ketoglutarate, 2-ketoadipate and, to a lesser extent, pyruvate served as amino group acceptors. This pattern suggests that this enzyme, previously designated as a lysine-6-aminotransferase, is actually an omega-aminotransferase. When 2-ketoadipate is used as substrate, the reaction product is 2-aminoadipic acid, which contributes to the pool of this intermediate available for penicillin biosynthesis. The N-terminal end of the purified 45-kDa omega-aminotransferase was sequenced and was found to be similar to the corresponding segment of the OAT1 protein of Emericella (Aspergillus) nidulans. This information was used to clone the gene encoding this enzyme.
Collapse
Affiliation(s)
- E M Martín de Valmaseda
- Area de Microbiología, Fac. CC. Biológicas y Ambientales, Universidad de León, Campus de Vegazana, s/n, Spain
| | | | | | | | | |
Collapse
|
15
|
Ullán RV, Casqueiro J, Naranjo L, Vaca I, Martín JF. Expression of cefD2 and the conversion of isopenicillin N into penicillin N by the two-component epimerase system are rate-limiting steps in cephalosporin biosynthesis. Mol Genet Genomics 2004; 272:562-70. [PMID: 15668772 DOI: 10.1007/s00438-004-1087-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Accepted: 10/20/2004] [Indexed: 10/26/2022]
Abstract
The conversion of isopenicillin N into penicillin N in Acremonium chrysogenum is catalyzed by an epimerization system that involves an isopenicillin N-CoA synthethase and isopenicillin N-CoA epimerase, encoded by the genes cefD1 and cefD2. Several transformants containing two to seven additional copies of both genes were obtained. Four of these transformants (TMCD26, TMCD53, TMCD242 and TMCD474) showed two-fold higher IPN epimerase activity than the untransformed A. chrysogenum C10, and produced 80 to 100% more cephalosporin C and deacetylcephalosporin C than the parental strain. A second class of transformants, including TMCD2, TMCD32 and TMCD39, in contrast, showed a drastic reduction in cephalosporin biosynthesis relative to the untransformed control. These transformants had no detectable IPN epimerase activity and did not produce cephalosporin C or deacetylcephalosporin C. They also expressed both endogenous and exogenous cefD2 genes only after long periods (72-96 h) of incubation, as shown by Northern analysis, and were impaired in mycelial branching in liquid cultures. The negative effect of amplification of the cefD1 - cefD2 gene cluster in this second class of transformants is not correlated with high gene dosage, but appears to be due to exogenous DNA integration into a specific locus, which results in a pleiotropic effect on growth and cefD2 expression.
Collapse
Affiliation(s)
- R V Ullán
- Institute of Biotechnology (INBIOTEC), Avda del Real N(o)1, 24006 León, Spain
| | | | | | | | | |
Collapse
|
16
|
Naranjo L, Martín de Valmaseda E, Casqueiro J, Ullán RV, Lamas-Maceiras M, Bañuelos O, Martín JF. Inactivation of the lys7 gene, encoding saccharopine reductase in Penicillium chrysogenum, leads to accumulation of the secondary metabolite precursors piperideine-6-carboxylic acid and pipecolic acid from alpha-aminoadipic acid. Appl Environ Microbiol 2004; 70:1031-9. [PMID: 14766586 PMCID: PMC348860 DOI: 10.1128/aem.70.2.1031-1039.2004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pipecolic acid serves as a precursor of the biosynthesis of the alkaloids slaframine and swainsonine (an antitumor agent) in some fungi. It is not known whether other fungi are able to synthesize pipecolic acid. Penicillium chrysogenum has a very active alpha-aminoadipic acid pathway that is used for the synthesis of this precursor of penicillin. The lys7 gene, encoding saccharopine reductase in P. chrysogenum, was target inactivated by the double-recombination method. Analysis of a disrupted strain (named P. chrysogenum SR1-) showed the presence of a mutant lys7 gene lacking about 1,000 bp in the 3'-end region. P. chrysogenum SR1- lacked saccharopine reductase activity, which was recovered after transformation of this mutant with the intact lys7 gene in an autonomously replicating plasmid. P. chrysogenum SR1- was a lysine auxotroph and accumulated piperideine-6-carboxylic acid. When mutant P. chrysogenum SR1- was grown with L-lysine as the sole nitrogen source and supplemented with DL-alpha-aminoadipic acid, a high level of pipecolic acid accumulated intracellularly. A comparison of strain SR1- with a lys2-defective mutant provided evidence showing that P. chrysogenum synthesizes pipecolic acid from alpha-aminoadipic acid and not from L-lysine catabolism.
Collapse
Affiliation(s)
- Leopoldo Naranjo
- Area de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, 24071 León, Spain
| | | | | | | | | | | | | |
Collapse
|
17
|
Bañuelos O, Naranjo L, Casqueiro J, Gutiérrez S, Martín JF. Co-transformation with autonomous replicating and integrative plasmids in Penicillium chrysogenum is highly efficient and leads in some cases to rescue of the intact integrative plasmid. Fungal Genet Biol 2003; 40:83-92. [PMID: 14516761 DOI: 10.1016/s1087-1845(03)00081-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The efficiency of co-transformation in Penicillium chrysogenum Wisconsin 54-1255 pyrG(-) and the fate of the transforming DNA were studied using an integrative (pEF43) and an autonomous replicating plasmid (pAM9L). The results showed a co-transformation frequency of nearly 70% of all transformants tested. The total efficiency of transformation was shown to be dependent on the plasmid marker used as transformant selection (i.e., markers in the integrative or autonomous replicating vector). Analysis of the plasmids re-isolated from several co-transformants showed that different populations of plasmids co-exist in the fungal host. Interestingly, in all co-transformants studied, the integrative plasmid was found to be replicating autonomously without integrating into the host genome. In some cases, co-integrates were formed by recombination between autonomous replicating (pAM9L) and integrative (pEF43) plasmids. However, unexpectedly in some cases, the non-reorganised pEF43 integrative plasmid used in the co-transformation assays was rescued from some co-transformants.
Collapse
Affiliation(s)
- Oscar Bañuelos
- Area de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, 24071 León, Spain
| | | | | | | | | |
Collapse
|
18
|
Naranjo L, Martin de Valmaseda E, Bañuelos O, Lopez P, Riaño J, Casqueiro J, Martin JF. Conversion of pipecolic acid into lysine in Penicillium chrysogenum requires pipecolate oxidase and saccharopine reductase: characterization of the lys7 gene encoding saccharopine reductase. J Bacteriol 2001; 183:7165-72. [PMID: 11717275 PMCID: PMC95565 DOI: 10.1128/jb.183.24.7165-7172.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pipecolic acid is a component of several secondary metabolites in plants and fungi. This compound is useful as a precursor of nonribosomal peptides with novel pharmacological activities. In Penicillium chrysogenum pipecolic acid is converted into lysine and complements the lysine requirement of three different lysine auxotrophs with mutations in the lys1, lys2, or lys3 genes allowing a slow growth of these auxotrophs. We have isolated two P. chrysogenum mutants, named 7.2 and 10.25, that are unable to convert pipecolic acid into lysine. These mutants lacked, respectively, the pipecolate oxidase that converts pipecolic acid into piperideine-6-carboxylic acid and the saccharopine reductase that catalyzes the transformation of piperideine-6-carboxylic acid into saccharopine. The 10.25 mutant was unable to grow in Czapek medium supplemented with alpha-aminoadipic acid. A DNA fragment complementing the 10.25 mutation has been cloned; sequence analysis of the cloned gene (named lys7) revealed that it encoded a protein with high similarity to the saccharopine reductase from Neurospora crassa, Magnaporthe grisea, Saccharomyces cerevisiae, and Schizosaccharomyces pombe. Complementation of the 10.25 mutant with the cloned gene restored saccharopine reductase activity, confirming that lys7 encodes a functional saccharopine reductase. Our data suggest that in P. chrysogenum the conversion of pipecolic acid into lysine proceeds through the transformation of pipecolic acid into piperideine-6-carboxylic acid, saccharopine, and lysine by the consecutive action of pipecolate oxidase, saccharopine reductase, and saccharopine dehydrogenase.
Collapse
Affiliation(s)
- L Naranjo
- Area of Microbiology, Faculty of Biology and Environmental Sciences, University of León, León, Spain
| | | | | | | | | | | | | |
Collapse
|
19
|
Fresquez PR, Huchton JD, Mullen MA, Naranjo L. Radionuclides in pinon pine (Pinus edulis) nuts from Los Alamos National Laboratory lands and the dose from consumption. J Environ Sci Health B 2000; 35:611-622. [PMID: 10968611 DOI: 10.1080/03601230009373296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food--the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of 3H, 137Cs, 90Sr, totU, 238Pu, 239,240Pu, and 241Am in soils (0- to 12-in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of 3H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN fromLANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 microSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 microSv). Soil-to-nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.
Collapse
Affiliation(s)
- P R Fresquez
- Environment, Safety and Health Division, Los Alamos National Laboratory, NM 87545, USA
| | | | | | | |
Collapse
|
20
|
Fresquez PR, Kraig DH, Mullen MA, Naranjo L. Radionuclides and trace elements in fish collected upstream and downstream of Los Alamos National Laboratory and the doses to humans from the consumption of muscle and bone. J Environ Sci Health B 1999; 34:885-899. [PMID: 10466108 DOI: 10.1080/03601239909373233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The purpose of this study was to determine radionuclide and trace element concentrations in bottom-feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for 3H, 90Sr, 137Cs, totU, 238Pu, 239,240Pu, and 241Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of 90Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p < 0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium-90 in fish muscle plus bone tissue significantly (p < 0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E-02 pCi g-1 [126E-02 Bq kg-1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E-02 pCi g-1 [518E-02 Bq kg-1]). The differences in 90Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (+/- 2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 +/- 0.1 mrem y-1 (1.0 +/- 1.0 microSv y-1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y-1 (1000 microSv y-1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p < 0.05) concentrations than in muscle of fish collected from background locations.
Collapse
Affiliation(s)
- P R Fresquez
- Environmental, Safety and Health Division, M887 Los Alamos National Laboratory, NM 87545, USA
| | | | | | | |
Collapse
|
21
|
Díaz-Araya G, Godoy L, Naranjo L, Squella JA, Letelier ME, Núñez-Vergara LJ. Antioxidant effects of 1,4-dihydropyridine and nitroso aryl derivatives on the Fe+3/ascorbate-stimulated lipid peroxidation in rat brain slices. Gen Pharmacol 1998; 31:385-91. [PMID: 9703206 DOI: 10.1016/s0306-3623(98)00034-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
1. Lipid peroxidation in rat brain slices was induced by Fe+3/ascorbate. 2. Brain lipid peroxidation, as measured by malondialdehyde formation, was inhibited by all the tested nitro aryl 1,4-dihydropyridine derivatives over a wide range of concentrations. The time-course antioxidant effects of the most representative agents were assessed. On the basis of both time-course and IC50 experiments the tentative order of antioxidant activity on rat brain slices could be: nicardipine>nisoldipine> (R,S/S,R)-furnidipine > (R,R/S,S)-furnidipine>nitrendipine>nimodipine> nifedipine. 3. 1,4-Dihydropyridine derivatives that lack of a nitro group in the molecule (isradipine, amlodipine) also inhibited lipid peroxidation in rat brain slices but at higher concentrations than that of nitro-substituted derivatives. 4. All the tested nitroso aryl derivatives [2,6-dimethyl-4-(2-nitrosophenyl)-3,5-pyridinedicar. boxylic acid dimethyl ester (NTP), nitrosotoluene, nitrosobenzene] were more potent inhibitors of lipid peroxidation than were the parent nitro compounds. In conclusion, on the basis of the IC50 values determined, the rank order of antioxidant potency for these derivatives can be established as: ortho-nitrosotoluene>NTP>nitrosobenzene.
Collapse
Affiliation(s)
- G Díaz-Araya
- Laboratory of Pharmacology, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago
| | | | | | | | | | | |
Collapse
|
22
|
Alvarez-Lueje A, Naranjo L, Núñez-Vergara LJ, Squella JA. Electrochemical study of nisoldipine: analytical application in pharmaceutical forms and photodegradation. J Pharm Biomed Anal 1998; 16:853-62. [PMID: 9580340 DOI: 10.1016/s0731-7085(97)00122-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The anodic and cathodic behavior of nisoldipine, 3-isobutyl-5-methyl-1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)pyridine-3 ,5-dicarboxylate, are reported. This drug belongs to the nitroaryl-1,4-dihydropyridine family, known as calcium channel antagonist and employed in therapeuticalls as peripheral and cerebral vasodilators, in the treatment of the arterial hypertension. The cathodic response corresponds to the reduction of the nitroaromatic group to generate the hydroxylamine derivative. The study by dc and d.p.p. reveals the appearance of four signals depending on pH: Signal I (pH 1-11.5) R - NO2 + 4H+ + 4e- --> R - NHOH + H2O; Signal II (pH 1-5) R - N+H2OH + 2H+ + 2e- --> RN+H3 + H2O; Signal III (pH > 11.5) R - NO2 + e- <--> R - NO2.-; Signal IV (pH > 11.5) R - NO2.- + 3e- + 4H+ --> R - NHOH. In contrast, the anodic response corresponds to the oxidation of the 1,4-dihydropyridine ring to generate the corresponding pyridine derivative. Both, cathodic (d.p.p.) and anodic signals (d.p.v.) were employed to develop analytical methodology for the determination of the drug. The repeatability of the measurements for both methods was adequate with R.S.D. of 1.4% (n = 10) and 2.1% (n = 10) for d.p.p. and d.p.v., respectively. Also recovery studies, 103.8% (R.S.D. 2.65%) by d.p.p. and 98.7% (R.S.D. 2.1%) by d.p.v. show that the accuracy and precision of the developed methods were adequate. The analytical methods were successfully applied to the determination of nisoldipine in both tablets and capsules. In addition, a preliminary study of the photostability of nisoldipine (using both UV and artificial day light) was completed. The identity of the main electroactive photodegradation products by GC with spectrometry detection is provided.
Collapse
Affiliation(s)
- A Alvarez-Lueje
- Bioelectrochemistry Laboratory, Chemical and Pharmaceutical Sciences Faculty, University of Chile, Santiago
| | | | | | | |
Collapse
|
23
|
Fresquez PR, Armstrong DR, Mullen MA, Naranjo L. The uptake of radionuclides by beans, squash, and corn growing in contaminated alluvial soils at Los Alamos National Laboratory. J Environ Sci Health B 1998; 33:99-121. [PMID: 9491570 DOI: 10.1080/03601239809373132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pinto beans (Phaselous vulgaris), sweet corn (Zea mays), and zucchini squash (Cucurbita pepo) were grown in a field pot study using alluvial floodplain soils contaminated with various radionuclides within Los Alamos Canyon (LAC) at Los Alamos National Laboratory, New Mexico. Soils as well as washed edible (fruit) and nonedible (stems and leaves) crop tissues were analyzed for tritium (3H), cesium (137Cs), strontium (90Sr), plutonium (238Pu and 239,240Pu), americium (241Am), and total uranium (totU). Most radionuclides, with the exception of 3H and totU, in soil and crop tissues from LAC were detected in significantly higher concentrations (p < 0.05) than in soil or crop tissues collected from regional background locations. Significant differences in radionuclide concentrations among crop species (squash were generally higher than beans or corn) and plant parts (nonedible tissue were generally higher than edible tissue) were observed. Most soil-to-plant concentration ratios for radionuclides in edible and nonedible crop tissues grown in soils from LAC were within default values in the literature commonly used in dose and risk assessment models. Overall, the maximum net positive committed effective dose equivalent (CEDE)--the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed--to a hypothetical 50-year resident that ingested 352 lb ([160 kg]; the maxiumum ingestion rate per person per year) of beans, corn, and squash in equal proportions was 74 mrem y-1 (740 microS y-1). This upper bound dose was below the International Commission on Radiological Protection permissible dose limit of 100 mrem y-1 (1000 microS y-1) from all pathways and corresponds to a risk of an excess cancer fatality of 3.7 x 10(-5) (37 in a million), which is also below the U.S. Environmental Protection Agency's guideline of 10(-4).
Collapse
Affiliation(s)
- P R Fresquez
- Environment, Safety and Health Division, Los Alamos National Laboratory, NM 87545, USA
| | | | | | | |
Collapse
|
24
|
Abstract
Glycosylated hemoglobin (HbA1) concentration was measured in 155 pre- and 30 postpartum patients to study its correlation with glucose metabolism and perinatal outcome in patients suspected of carbohydrate intolerance during pregnancy. Though the mean HbA1 values were significantly higher in gestational diabetics compared to normal pregnant controls, the large overlap between HbA1 levels of diabetic patients and levels in the of normal range, make HbA1 an unreliable screening device for diabetes. However, if the HbA1 level was elevated in patients suspected of carbohydrate intolerance, but who had a normal glucose tolerance test, the perinatal outcome in terms of macrosomia and neonatal metabolic abnormalities was similar to that of the group with gestational diabetes. HbA1 measurements should be obtained in these women, and, if elevated, maternal and fetal surveillance is recommended. HbA1 level is not a useful predictor of birthweight, though may be of value as a postpartum screen for unrecognized diabetes and may help discriminate between a constitutionally large but otherwise normal newborn and a large infant of a diabetic mother.
Collapse
|
25
|
Jarpa S, Mordojovich E, Naranjo L, De La Torre JM. [The posterior vagus trunk and its connections with the secretory areas of the stomach: an anatomical study (author's transl)]. Rev Med Chil 1980; 108:1109-11. [PMID: 7302407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|