US 5,472,859 AGranted

Enzymatic method for synthesis of cellulose 1

OwnerR. Malcolm Brown, Jr., Shiro Kobayashi +6inventors

InventorsR. Malcolm Brown, Jr., Shiro Kobayashi, Krystyna Kudlicka, Shigenori Kuga, Jong Lee, Likun Li, Kazuo Okuda, Shin-Ichiro Shoda

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Abstract

The present invention discloses a method of synthesizing a novel form of cellulose I as well as methods of synthesizing a novel form of cellulose I in vitro. One method comprises contacting an activated saccharide substrate with an endoglucanase in an appropriate organic solvent/buffer ratio. The invention also encompasses a partially purified endoglucanase and a method of synthesizing cellooligosaccharides. A second method comprises contacting a nucleotide sugar with a purified glycosyl transferase in an appropriate buffer medium to insure polymerization and crystallization of parallel glucan chains from the enzyme/micelle complex to form cellulose I.

Claims4

Dependent claims

A method of producing cellulose I, the method comprising contacting cellobiosyl fluoride with a Trichoderma viride endoglucanase having an isoelectric point of about pH 3.6, obtained by the steps of:

(a) chromatography of a crude Trichoderma viride cellulase preparation over a polyacrylamide gel having a fractionation range of 1,500 to 20,000 daltons;
(b) isoelectric focusing;
and
(c) chromatography over a polyacrylamide gel having a fractionation range of 5,000 to 100,000 daltons;
or alternatively, obtained by the steps of:
(d) 37%-45% ammonium sulfate fractionation of a crude Trichoderma viride cellulase preparation;
(e) chromatography over a polyacrylamide gel having a fractionation range of 1,500 to 20,000 daltons;
(f) isoelectric focusing;
and
(g) chromatography over a polyacrylamide gel having a fractionation range of 5,000 to 1000,000 daltons;
wherein said endoglucanase is contained in micelles comprising an aqueous buffer and acetonitrile in a ratio of about 2:1.

8 more elements

Dependencies are inferred from the claim text.