Publications (9)33.13 Total impact
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Article: Production, purification, and characterization of human alpha1 proteinase inhibitor from Aspergillus niger.
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ABSTRACT: Human alpha one proteinase inhibitor (alpha1-PI) was cloned and expressed in Aspergillus niger, filamentious fungus that can grow in defined media and can perform glycosylation. Submerged culture conditions were established using starch as carbon source, 30% dissolved oxygen concentration, pH 7.0 and 28 degrees C. Eight milligrams per liter of active alpha1-PI were secreted to the growth media in about 40 h. Controlling the protein proteolysis was found to be an important factor in the production. The effects of various carbon sources, pH and temperature on the production and stability of the protein were tested and the product was purified and characterized. Two molecular weights variants of the recombinant alpha1-PI were produced by the fungus; the difference is attributed to the glycosylated part of the molecule. The two glycoproteins were treated with PNGAse F and the released glycans were analyzed by HPAEC, MALDI/TOF-MS, NSI-MS(n), and GC-MS. The MALDI and NSI- full MS spectra of permethylated N-glycans revealed that the N-glycans of both variants contain a series of high-mannose type glycans with 5-20 hexose units. Monosaccharide analysis showed that these were composed of N-acetylglucos-amine, mannose, and galactose. Linkage analysis revealed that the galactosyl component was in the furanoic conformation, which was attaching in a terminal non-reducing position. The Galactofuranose-containing high-mannnose type N-glycans are typical structures, which recently have been found as part of several glycoproteins produced by Aspergillus niger.Biotechnology and Bioengineering 09/2008; 102(3):828-44. · 3.95 Impact Factor -
Article: Production, purification, and characterization of human α1 proteinase inhibitor from Aspergillus niger
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ABSTRACT: Human alpha one proteinase inhibitor (α1-PI) was cloned and expressed in Aspergillus niger, filamentious fungus that can grow in defined media and can perform glycosylation. Submerged culture conditions were established using starch as carbon source, 30% dissolved oxygen concentration, pH 7.0 and 28°C. Eight milligrams per liter of active α1-PI were secreted to the growth media in about 40 h. Controlling the protein proteolysis was found to be an important factor in the production. The effects of various carbon sources, pH and temperature on the production and stability of the protein were tested and the product was purified and characterized. Two molecular weights variants of the recombinant α1-PI were produced by the fungus; the difference is attributed to the glycosylated part of the molecule. The two glycoproteins were treated with PNGAse F and the released glycans were analyzed by HPAEC, MALDI/TOF-MS, NSI-MSn, and GC-MS. The MALDI and NSI- full MS spectra of permethylated N-glycans revealed that the N-glycans of both variants contain a series of high-mannose type glycans with 5–20 hexose units. Monosaccharide analysis showed that these were composed of N-acetylglucos-amine, mannose, and galactose. Linkage analysis revealed that the galactosyl component was in the furanoic conformation, which was attaching in a terminal non-reducing position. The Galactofuranose-containing high-mannnose type N-glycans are typical structures, which recently have been found as part of several glycoproteins produced by Aspergillus niger. Biotechnol. Bioeng. 2009; 102: 828–844. © 2008 Wiley Periodicals, Inc.Biotechnology and Bioengineering 08/2008; 102(3):828 - 844. · 3.95 Impact Factor -
Article: Production of human α<sub>1 </sub>proteinase inhibitor from Aspergillus niger
Microbial Cell Factories. 01/2006; -
Article: Antifungal effect and possible mode of activity of a compound from the marine sponge Dysidea herbacea.
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ABSTRACT: Assessment of antifungal activity of a compound isolated from the marine sponge Dysidea herbacea against the fungal pathogens Candida (primarily C. albicans) and Aspergillus (primarily A. fumigatus) species, and investigations of the possible mode of activity of the compound. Freeze dried sponges were extracted with EtOAc-MeOH. Bioassay guided separation was used to identify the active compound. Antifungal activity was assessed in vitro by a modified NCCLS technique. For determination of the possible mode of activity of the compound we tested the effect on fungal cellular morphology (light, scanning and transmission electron microscopy) and possible site of activity in the fungal cells, such as cell membrane (ion leakage kinetics) as well as toxicity (cytotoxicity tests). The active compound was determined to be 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy) phenol. This compound exhibited in vitro activity against the tested fungal pathogens. The experiments on the mode of activity revealed that there are significant changes in fungal cell morphology, as demonstrated by scanning and transmission electron microscopy. The compound, apparently, affects the fungal cell membrane, expressed primarily in leakage of potassium ions from the fungal cells. Two other bromo diphenyl ethers were also found to be active. Further experiments in in vivo models are planned.Journal of Infection 07/2005; 50(5):453-60. · 4.13 Impact Factor -
Article: Eunicellin diterpenes from two Kenyan soft corals.
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ABSTRACT: Six new eunicellin diterpenes designated klyxumines A and B (1, 2) and epoxycladines A-D (3-6) were isolated from Klyxum flaccidum and Cladiella kashmani, collected in Kenya. The structures of the compounds were elucidated by interpretation of MS, COSY, HMQC, HMBC, and NOESY data.Journal of Natural Products 02/2005; 68(1):19-25. · 3.13 Impact Factor -
Article: Kitungolides A, B, and C, new diterpenes from a soft coral of a new genus.
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ABSTRACT: Three novel compounds, designated kitungolides A (1), B (2), and C (3), were isolated from a soft coral of a new genus collected at Kitungamwe, Kenya. The three new compounds are of a unique heterotricyclic skeleton. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, COSY, HMQC, HMBC, and NOESY experiments. [structure: see text]Organic Letters 04/2004; 6(5):755-8. · 5.86 Impact Factor -
Article: Barrenazine A and B; two new cytotoxic alkaloids from an unidentified tunicate.
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ABSTRACT: [structure: see text] Two novel compounds, barrenazine A (1) and B (2), were isolated from an unidentified tunicate collected at Barren Islands, Madagascar. The two new compounds are of an unprecedented heterocyclic skeleton, namely 1,3,4,6,8,9-hexahydrodipyridino[3,4-b:3',4'-e]pyrazine. The structures of the two alkaloids were elucidated by interpretation of MS, COSY, HMQC, HMBC, NOESY, and (15)N-HMBC data. Barrenazine A exhibits mild cytotoxicity against LOVO-DOX colon carcinoma (with a GI(50) value of 0.9 g/mL)Organic Letters 08/2003; 5(14):2433-5. · 5.86 Impact Factor -
Article: Didmolamide A and B, two new cyclic hexapeptides from the marine ascidian Didemnum molle.
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ABSTRACT: Two novel cyclic hexapeptides, didmolamides A and B, were isolated from the compound ascidian Didemnum molle collected in Madagascar. The structure of the two peptides was elucidated by interpretation of MS, COSY, HMQC, and HMBC data. The absolute configuration of all amino acids was determined to be l using Marfey's method for HPLC.Journal of Natural Products 05/2003; 66(4):575-7. · 3.13 Impact Factor -
Article: Halichondramine, a new tetracyclic bipiperidine alkaloid from the marine sponge Halichondria sp.
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ABSTRACT: Halichondramine (1), a new tetracyclic alkylbipiperidine alkaloid, has been isolated from the marine sponge Halichondria sp., collected in the Dahlak archipelago (the Red Sea), Eritrea. The structure of halichondramine was elucidated by interpretation of MS, COSY, HMQC, HMBC, TOCSY, and HSQC-TOCSY data.Journal of Natural Products 12/2002; 65(11):1738-41. · 3.13 Impact Factor
Top co-authors
Top Journals
Institutions
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2008
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National Institutes of Health
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Bethesda, MD, USA
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2002–2004
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Tel Aviv University
- Department of Chemistry
Tel Aviv, Tel Aviv, Israel
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