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Luo CM, Ke LF, Huang XY, Zhuang XY, Guo ZW, Xiao Q, Chen J, Chen FQ, Yang QM, Ru Y, Weng HF, Xiao AF, Zhang YH. Efficient biosynthesis of prunin in methanol cosolvent system by an organic solvent-tolerant α-L-rhamnosidase from Spirochaeta thermophila. Enzyme Microb Technol 2024; 175:110410. [PMID: 38340378 DOI: 10.1016/j.enzmictec.2024.110410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/29/2024] [Accepted: 02/03/2024] [Indexed: 02/12/2024]
Abstract
Prunin of desirable bioactivity and bioavailability can be transformed from plant-derived naringin by the key enzyme α-L-rhamnosidase. However, the production was limited by unsatisfactory properties of α-L-rhamnosidase such as thermostability and organic solvent tolerance. In this study, biochemical characteristics, and hydrolysis capacity of a novel α-L-rhamnosidase from Spirochaeta thermophila (St-Rha) were investigated, which was the first characterized α-L-rhamnosidase for Spirochaeta genus. St-Rha showed a higher substrate specificity towards naringin and exhibited excellent thermostability and methanol tolerance. The Km of St-Rha in the methanol cosolvent system was decreased 7.2-fold comparing that in the aqueous phase system, while kcat/Km value of St-Rha was enhanced 9.3-fold. Meanwhile, a preliminary conformational study was implemented through comparative molecular dynamics simulation analysis to explore the mechanism underlying the methanol tolerance of St-Rha for the first time. Furthermore, the catalytic ability of St-Rha for prunin preparation in the 20% methanol cosolvent system was explored, and 200 g/L naringin was transformed into 125.5 g/L prunin for 24 h reaction with a corresponding space-time yield of 5.2 g/L/h. These results indicated that St-Rha was a novel α-L-rhamnosidase suitable for hydrolyzing naringin in the methanol cosolvent system and provided a better alternative for improving the efficient production yield of prunin.
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Affiliation(s)
- Chen-Mu Luo
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China
| | - Li-Fan Ke
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China
| | - Xiang-Yu Huang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China
| | - Xiao-Yan Zhuang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Ze-Wang Guo
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Qiong Xiao
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Jun Chen
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Fu-Quan Chen
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Qiu-Ming Yang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Yi Ru
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - Hui-Fen Weng
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China
| | - An-Feng Xiao
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China.
| | - Yong-Hui Zhang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China.
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Abstract
Using a plasmid substrate which integrates into the genome, we determined that the rate of homologous recombination was suppressed by p53. Human tumor cell lines, mutant or null for p53 had recombination rates 10000-times greater than primary fibroblasts. When isogenic cell pairs from tumor cells or primary fibroblasts were compared, differing only in one genetic change which inactivated p53, the recombination rate increased > 100-fold. Functional inactivation of p53 by dominant mutant p53, by large T antigen of SV40 virus, by E6 protein of human papilloma virus, or by genetic deletion led to the same result. Our results suggest that p53 suppresses spontaneous homologous recombination, and that p53 is not required for recombination to proceed. The mechanism of recombination suppression may be related to the reported association of p53 with Rad 51, but the functional consequences of this association are not yet established. It is suggested that suppression of homologous recombination is the means by which p53 maintains genetic stability.
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Affiliation(s)
- K L Mekeel
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA
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Li JY, Chen Y, Luo CM. [The clinical research of the tooth acid erosion disease in workers related to acid jobs]. Shanghai Kou Qiang Yi Xue 1996; 5:200-2. [PMID: 15159984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Through investigation into 1671 workers who do six acid related jobs in fourteen factories,and 501 workers who work in non-acid condition in contrast.The paper has worked out the criteria of diagnosing occupational acid erosion disease,including the classified criteria of diagnosing single tooth acid erosion disease and the criteria of diagnosing different degrees of the tooth acid erosion disease in the oral cavity.It has also been found out that these are close relationships between the rate of suffering the occupational tooth acid erosion disease and the degree of the erosion,on the one hand and density of acid fog in the air and the types of acid workers are exposed ton and the length of the years working in such environment.
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Affiliation(s)
- J Y Li
- Department of Stomatology,Shanghai No.6 Hospital.Shanghai 200233,China
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Luo CM, Tang W, Mekeel KL, DeFrank JS, Anné PR, Powell SN. High frequency and error-prone DNA recombination in ataxia telangiectasia cell lines. J Biol Chem 1996; 271:4497-503. [PMID: 8626804 DOI: 10.1074/jbc.271.8.4497] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [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] [Indexed: 01/31/2023] Open
Abstract
The only specific DNA repair defect found in ataxia telangiectasia (A-T) cells is mis-repair of cleaved DNA. In this report we measured DNA recombination, given its role in DNA repair and genetic instability. Using plasmids containing selectable reporter genes, we found a higher frequency of both chromosomal recombination (>100 times) and extra-chromosomal recombination (27 times) in SV40-transformed A-T cell lines compared with in an SV40-transformed normal fibroblast cell line. Southern analysis of single A-T colonies exhibiting post-integration recombination revealed that 24/27 had undergone aberrant rearrangements; recombination in normal fibroblast colonies was achieved by gene conversion in 8/11 clones and 10/11 clones showed unchanged copies of the plasmid. Using co-transfection of two integrating plasmids, each containing a separate deletion in the xgprt reporter gene, the 27 times difference in extra-chromosomal recombination was found when the plasmids were cleaved at a distance from the reporter gene. When the plasmids were cleaved within the reporter gene, the co-transfection frequency was reduced in A-T, but was increased in normal cells. We conclude that A-T cell lines have not only a high frequency chromosomal and extra-chromosomal recombination, but also exhibit error-prone recombination of cleaved DNA.
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Affiliation(s)
- C M Luo
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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Zheng YC, Xie JM, Wei B, Zhu ZR, Wu YQ, Ni SH, Tan ZJ, Luo CM, Liu X, Zhou Y. Microcomputer system for automatic identification of the Cryptococcus neoformans and its clinical application. J Tongji Med Univ 1995; 15:41-4. [PMID: 7783263 DOI: 10.1007/bf02887884] [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: 01/27/2023]
Abstract
In this study, microcomputer image processing and pattern recognition technology, and the knowledge of morphology and optical characteristics of Cryptococcus neoformans were used for identification of Cryptococcus neoformans. Four groups of mice were lethally infected with standard strain, Wuhan strain, American B-2643 strain and Var. Shanghainesis of the Cryptococcus neoformans. The samples collected included mice brain, lung, kidney, liver, small intestine tissue and were observed under a light microscope. More than 600 images of the fungus were input into a microcomputer. A system of computer for automatic identification of the Cryptococcus neoformans was developed. The technique involved image preprocessing, image segmenting, coding of line-length on the edge, curve fitting, extracting of image feature, building of image library and feature data bank etc.. And then, 768 images of the clinical samples and other fungus samples whose morphological features tend to be confused with Cryptococcus neoformans were input into microcomputer and subjected to automatic identification. The Cryptococcus neoformans was accurately identified within 15 min, and the consistency rate with results of routine culture was 98%.
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Affiliation(s)
- Y C Zheng
- Department of Dermatology, Xiehe Hospital, Tongji Medical University, Wuhan
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Zhao ML, Luo CM, Long F, Chen J, Tang LY. [Growth capability of epithelial cell line of human poorly differentiated nasopharyngeal carcinoma and its response to Chinese medicinal herbs and marine drugs]. Zhonghua Zhong Liu Za Zhi 1988; 10:98-101. [PMID: 3208662] [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] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
By 3H-TdR incorporation, dye exclusion and cell colony-forming tests, the capability of short-term in vitro growth of the epithelial cell line of human poorly differentiated nasopharyngeal carcinoma (CNE-2Z) was assayed. At the same time, its response to 54 kinds of Chinese medicinal herbs and marine drugs was studied. The results showed that the 3H-TdR incorporation rate of cells was 1.8 +/- 0.02%, reproduction rate was 60.9 +/- 13.0% and colony-forming rate, 40.8 +/- 3.5%. As to the ratios of the three cell growth indexes and response to medicines, the Chinese medicinal herbs and marine drugs causing the reduction of colony-forming and cell survival ratios were predominant (64.8% and 40.7%). The results indicate that the majority of drugs possess the cytotoxic and inhibitory effect on cell reproduction to different degrees. The composite cell response to every kind of drug could be divided into 6 types: descending, ascending, peaked, valley-like, depressed and stable. The depressing type drugs might inhibit or arrest the cell growth of nasopharyngeal carcinoma and are worthy of further study.
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