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Grafting modification of okra mucilage: Recent findings, applications, and future directions. Carbohydr Polym 2020; 246:116653. [DOI: 10.1016/j.carbpol.2020.116653] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/08/2020] [Accepted: 06/14/2020] [Indexed: 01/16/2023]
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Park HS, Park JH, Lee HS, Ryu K. Enzymatic Synthesis of Flame Retardant Phenolic Polymers Catalyzed by Horseradish Peroxidase. KOREAN CHEMICAL ENGINEERING RESEARCH 2013. [DOI: 10.9713/kcer.2013.51.1.111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Synthesis and characterization of a novel soil stabilizer based on biodegradable poly(aspartic acid) hydrogel. KOREAN J CHEM ENG 2009. [DOI: 10.1007/s11814-008-0176-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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4
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Harada A, Osaki M, Takashima Y, Yamaguchi H. Ring-opening polymerization of cyclic esters by cyclodextrins. Acc Chem Res 2008; 41:1143-52. [PMID: 18690725 DOI: 10.1021/ar800079v] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Synthetic polymers, typically prepared by addition polymerization or stepwise polymerization, are used constantly in our daily lives. In recent years, polymer scientists have focused on more environmentally friendly synthetic methods such as mild reaction conditions and biodegradable condensation polymers, including polyesters and polyamides. However, challenges remain in finding greener methods for the synthesis of polymers. Although reactions carried out in water are more environmentally friendly than those in organic solvents, aqueous media can lead to the hydrolysis of condensation polymers. Furthermore, bulk polymerizations are difficult to control. In biological systems, enzymes synthesize most polymers (proteins, DNAs, RNAs, and polysaccharides) in aqueous environments or in condensed phases (membranes). Most enzymes, such as DNA polymerases, RNA polymerases, and ribosomes, form doughnutlike shapes, which encircle the growing polymer chain. As biopolymers form, the active sites and the substrate-combining sites are located at the end of the growing polymer chain and carefully control the polymerization. Therefore, a synthetic catalyst that could insert the monomers between the active site and binding site would create an ideal biomimetic polymerization system. In this Account, we describe cyclodextrins (CDs) as catalysts that can polymerize cyclic esters (lactones and lactides). CDs can initiate polymerizations of cyclic esters in bulk without solvents (even water) to give products in high yields. During our studies on the polymerization of lactones by CDs in bulk, we found that CDs function not only as initiators (catalysts) but also as supporting architectures similar to chaperone proteins. CDs encircle a linear polymer chain so that the chain assumes the proper conformation and avoids coagulation. The CDs can mimic the strategy that living systems use to prepare polymers. Thus, we can obtain polyesters tethered to CDs without employing additional solvents or cocatalysts. Although CD has many hydroxyl groups, only one secondary hydroxyl group attaches to the polyester chain. In addition, the polymerization is highly specific for monomer substrates. We believe that this is the first system in which the catalyst includes monomers initially and subsequently activates the included monomers. The catalyst then inserts the monomers between the binding site and the growing chain. Therefore, this system should provide a new environmentally friendly route to produce biodegradable functional polymers.
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Affiliation(s)
- Akira Harada
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Motofumi Osaki
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yoshinori Takashima
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Hiroyasu Yamaguchi
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Joseph B, Ramteke PW, Thomas G. Cold active microbial lipases: some hot issues and recent developments. Biotechnol Adv 2008; 26:457-70. [PMID: 18571355 DOI: 10.1016/j.biotechadv.2008.05.003] [Citation(s) in RCA: 267] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Accepted: 05/09/2008] [Indexed: 10/22/2022]
Abstract
Lipases are glycerol ester hydrolases that catalyze the hydrolysis of triglycerides to free fatty acids and glycerol. Lipases catalyze esterification, interesterification, acidolysis, alcoholysis and aminolysis in addition to the hydrolytic activity on triglycerides. The temperature stability of lipases has regarded as the most important characteristic for use in industry. Psychrophilic lipases have lately attracted attention because of their increasing use in the organic synthesis of chiral intermediates due to their low optimum temperature and high activity at very low temperatures, which are favorable properties for the production of relatively frail compounds. In addition, these enzymes have an advantage under low water conditions due to their inherent greater flexibility, wherein the activity of mesophilic and thermophilic enzymes are severely impaired by an excess of rigidity. Cold-adapted microorganisms are potential source of cold-active lipases and they have been isolated from cold regions and studied. Compared to other lipases, relatively smaller numbers of cold active bacterial lipases were well studied. Lipases isolated from different sources have a wide range of properties depending on their sources with respect to positional specificity, fatty acid specificity, thermostability, pH optimum, etc. Use of industrial enzymes allows the technologist to develop processes that closely approach the gentle, efficient processes in nature. Some of these processes using cold active lipase from C. antarctica have been patented by pharmaceutical, chemical and food industries. Cold active lipases cover a broad spectrum of biotechnological applications like additives in detergents, additives in food industries, environmental bioremediations, biotransformation, molecular biology applications and heterologous gene expression in psychrophilic hosts to prevent formation of inclusion bodies. Cold active enzymes from psychrotrophic microorganisms showing high catalytic activity at low temperatures can be highly expressed in such recombinant strains. Thus, cold active lipases are today the enzymes of choice for organic chemists, pharmacists, biophysicists, biochemical and process engineers, biotechnologists, microbiologists and biochemists.
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Affiliation(s)
- Babu Joseph
- Department of Microbiology and Microbial Technology, College of Biotechnology and Allied Sciences, Allahabad Agricultural Institute-Deemed University, Uttar Pradesh, India
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Modification of lipase fromCandida rugosa with poly(ethylene oxide-co-maleic anhydride) and its separation using aqueous two-phase partition system. KOREAN J CHEM ENG 2006. [DOI: 10.1007/bf02706801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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7
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Characteristics of the lipase fromCandida rugosa modified with copolymers of polyoxyethylene derivative and maleic acid anhydride. KOREAN J CHEM ENG 2005. [DOI: 10.1007/bf02719420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Ikeda R, Tanaka H, Uyama H, Kobayashi S. Synthesis and curing behaviors of a crosslinkable polymer from cashew nut shell liquid. POLYMER 2002. [DOI: 10.1016/s0032-3861(02)00062-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Al-Azemi TF, Bisht KS. One-step synthesis of polycarbonates bearing pendant carboxyl groups by lipase-catalyzed ring-opening polymerization. ACTA ACUST UNITED AC 2002. [DOI: 10.1002/pola.10212] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Affiliation(s)
- S Kobayashi
- Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan.
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Abstract
A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity.
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Affiliation(s)
- S Kobayashi
- Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, Japan.
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Uyama H, Kobayashi S, Morita M, Habaue S, Okamoto Y. Chemoselective Ring-Opening Polymerization of a Lactone Having exo-Methylene Group with Lipase Catalysis. Macromolecules 2001. [DOI: 10.1021/ma010893v] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Ikeda R, Uyama H, Kobayashi S. Laccase-Catalyzed Curing of Vinyl Polymers Bearing a Phenol Moiety in the Side Chain. Polym J 2001. [DOI: 10.1295/polymj.33.540] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Takamoto T, Shirasaka H, Uyama H, Kobayashi S. Lipase-Catalyzed Hydrolytic Degradation of Polyurethane in Organic Solvent. CHEM LETT 2001. [DOI: 10.1246/cl.2001.492] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mita N, Tawaki SI, Uyama H, Kobayashi S. Molecular Weight Control of Polyphenols by Enzymatic Copolymerization of Phenols. Polym J 2001. [DOI: 10.1295/polymj.33.374] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Ikeda R, Tanaka H, Uyama H, Kobayashi S. A New Crosslinking Method of Vinyl Polymers Having a Phenol Moiety via Oxidative Coupling. Polym J 2001. [DOI: 10.1295/polymj.33.959] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Morawski B, Lin Z, Cirino P, Joo H, Bandara G, Arnold FH. Functional expression of horseradish peroxidase in Saccharomyces cerevisiae and Pichia pastoris. PROTEIN ENGINEERING 2000; 13:377-84. [PMID: 10835112 DOI: 10.1093/protein/13.5.377] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The ability to engineer proteins by directed evolution requires functional expression of the target polypeptide in a recombinant host suitable for construction and screening libraries of enzyme variants. Bacteria and yeast are preferred, but eukaryotic proteins often fail to express in active form in these cells. We have attempted to resolve this problem by identifying mutations in the target gene that facilitate its functional expression in a given recombinant host. Here we examined expression of HRP in Saccharomyces cerevisiae. Through three rounds of directed evolution by random point mutagenesis and screening, we obtained a 40-fold increase in total HRP activity in the S.cerevisiae culture supernatant compared with wild-type, as measured on ABTS ¿2, 2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (260 units/l/OD(600)). Genes from wild-type and two high-activity clones were expressed in Pichia pastoris, where the total ABTS activity reached 600 units/l/OD(600) in shake flasks. The mutants show up to 5.4-fold higher specific activity towards ABTS and 2.3-fold higher specific activity towards guaiacol.
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Affiliation(s)
- B Morawski
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, Pasadena, CA 91125, USA
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Abstract
Biocatalysis inherently offers the prospect of clean industrial processing and has become an accepted technology throughout most sectors. The convergence of biology and chemistry has enabled a plethora of industrial opportunities to be targeted, while discoveries in biodiversity and the impact of molecular biology and computational science are extending the range of natural and engineered biocatalysts that can be customised for clean industrial requirements.
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Affiliation(s)
- A T Bull
- Research School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK.
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