Chemoenzymatic synthesis of novel sucrose-containing polymers

Patil, Damodar R.; Dordick, Jonathan S.; Rethwisch, David G.

doi:10.1021/ma00011a068

Cited by 100 publications

(59 citation statements)

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“…In addition to the obvious advantage of enhancing the solubilities of organic substrates, organic solvents can lead to unusual chemistry when enzyme-catalyzed reactions that are infeasible in an aqueous medium become favored in a nonaqueous one (7). In organic solvents, serine proteases are promising catalysts for organic synthesis and the preparation of unusual polymers (8)(9)(10)(11). A triple variant of subtilisin E with enhanced activity in dimethylformamide (DMF) was described in an earlier report (12).…”

mentioning

confidence: 99%

Tuning the activity of an enzyme for unusual environments: sequential random mutagenesis of subtilisin E for catalysis in dimethylformamide.

Chen

Arnold

1993

Proc. Natl. Acad. Sci. U.S.A.

485

235

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Random mutagenesis has been used to engineer the protease subtilisin E to function in a highly nonnatural environment-high concentrations of a polar organic solvent. Sequential rounds of mutagenesis and screening have yielded a variant (PC3) that hydrolyzes a peptide substrate 256 times more efficiently than wild-type subtiisin in 60% dimethylformamide. PC3 subtilisin E and other variants containing different combinations of amino acid substitutions are effective catalysts for transesterification and peptide synthesis in dimethylformamide and other organic media. Starting with a variant containing four effective amino acid substitutions (D60N, D97G, Q103R, and N218S; where, for example, D60N represents Asp-60 -) Asn), six additional mutations (G131D, E156G, N181S, S182G, S188P, and T255A) were generated during three sequential rounds of mutagenesis and screening. The 10 substitutions are clustered on one face of the enzyme, near the active site and substrate binding pocket, and all are located in loops that connect core secondary structure elements and exhibit considerable sequence variability in subtilisins from different sources. These variable surface loops are effective handles for "tuning" the activity of subtilisin. Seven of the 10 amino acid substitutions in PC3 are found in other natural subtilisins. Great variability is exhibited among naturally occurring sequences that code for similar three-dimensional structures-it is possible to make use of this sequence flexibility to engineer enzymes to exhibit features not previously developed (or required) for function in vivo.With exquisite substrate specificities and high reaction selectivities, enzymes offer tremendous advantages for chemical synthesis. Nonetheless, practical applications of enzyme catalysis have been limited, due in large part to relatively poor stabilities and catalytic activities under the conditions that characterize industrial processes: high temperatures, extremes of pH, or nonaqueous solvents. Enzymes evolved for the survival benefit of an organism may not exhibit features essential for in vitro application.A large body of experience in tailoring enzyme properties by making selected substitutions of the enzyme's amino acid sequence has accumulated. A "rational design" approach involving site-directed mutagenesis is inefficient, however, in the absence of detailed structural information or when the molecular basis for the property of interest is poorly understood. In such cases, random mutagenesis combined with selection or screening can be a useful alternative for generating both the desired improvements and a data base for future rational approaches to protein design. Random mutagenesis has been used to enhance or alter various enzyme features, including thermal stability (1-3), alkaline stability (4), and substrate specificity (5), and to recover the catalytic The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U...

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confidence: 99%

Tuning the activity of an enzyme for unusual environments: sequential random mutagenesis of subtilisin E for catalysis in dimethylformamide.

Chen

Arnold

1993

Proc. Natl. Acad. Sci. U.S.A.

485

235

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“…high temperature or strict exclusion of moisture) [5,6,16]and the metal catalysts may be problematic for certain product end uses especially for medical use. [7] Lipase can catalyze esterification reactions at mild temperatures [8][9][10].These characteristics motivated theirs study as catalysts for polyesterifications.Recently,enzymatic designing and synthesizing of environmentally acceptable polymeric materials has become an effective method. Unless chemical catalysis lipase catalyzed condensation polymerizations are metal-free and enzymes are derived from natural resources.…”

Section: Introductionmentioning

confidence: 99%

Chemo enzymatic Synthesis for Poly3-hydroxypropionate in Solvent-free System

Li¹,

Li²,

Yao³

et al. 2016

Proceedings of the 2016 6th International Conference on Mechatronics, Computer and Education Informationization (MCEI 2016)

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“…For this, the development of short and easy routes for the preparation of larger quantities of these target molecules was necessary. A high degree of regioselectivity can be achieved by the enzymatic approach (Patil et al, 1991;Potier et al, 2000), although some disadvantages and limitations can be found in the use of enzymes (low stability of the enzymes in organic solvents or the correct choice of reagents for introducing the unsaturation, (Chen and Park, 2000). The functionalization of carbohydrates normally involves various protection-deprotection steps, which take a lot of experimental time (Jarosz and Mach, 2002).…”

Section: Introductionmentioning

confidence: 99%

“…Sucrose-containing polymers, having a polyvinyl backbone and pendant sucrose moieties, have been obtained by polymerization or copolymerization of sucrose derivatives -esters, ethers, and acetals, bearing a carbon-carbon double bond (Fig. 5), (Fanton et al, 1992;Ferreira et al, 2000;Jhurry et al, 1992;Patil et al, 1991). The monomers have been prepared either by multistep synthesis, leading to defined compounds and subsequently a well-defined polymerization processes (Fig.…”

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confidence: 99%