US4167447A
Expired / Lapsed
US
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Method for insolubilizing enzymes on chitosan
Assignee: United States Department of Agriculture
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Filing: 1978-03-24
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Granted: 1979-09-11
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Expires: 1998-03-24
Abstract
Abstract Insolubilized but active enzymes are prepared in a variety of ways. In one embodiment of the invention an aqueous solution of an enzyme is mixed with chitosan dissolved in water at pH 3-7 and an insolubilized product is precipitated therefrom by addition of alkali or a source of sulfate ions. Another embodiment of the invention involves contacting solid chitosan sulfate with an aqueous solution of the enzyme to be immobilized. In yet another embodiment of the invention solid chitosan is cross-linked with a polyfunctional cross-linking agent and then contacted with an aqueous solution of an enzyme. Enzymes insolubilized in accordance with the invention retain a substantial part of their original activity.
Inventors
- 👤 Merle S. Masri
- 👤 Virginia G. Randall
- 👤 William L. Stanley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:51
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/02; C12N11/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
70 words
A process for preparing an insoluble but active enzyme, which comprises (a) dissolving a solble active enzyme in water, (b) dissolving chitosan in water at pH 3-7, (c) mixing the aqueous solution of the enzyme with the solution of chitosan, and (d) precipitating an insoluble but active enzyme from the mixture by addition thereto of an agent selected from the group consisting of alkaline agents and sources of sulfate ions.
Claim 2
Dependent Claim
70 words
A process for preparing an insoluble but active enzyme, which comprises (a) dissolving a solble active enzyme in water, (b) dissolving chitosan in water at pH 3-7, (c) mixing the aqueous solution of the enzyme with the solution of chitosan, and (d) precipitating an insoluble but active enzyme from the mixture by addition thereto of an agent selected from the group consisting of alkaline agents and sources of sulfate ions.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the enzyme and chitosan are simultaneously dissolved in water at pH 3-7.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the enzyme is a sugar-hydrolyzing enzyme.
Claim 5
Dependent Claim
10 words
The process of claim 1 wherein the enzyme is invertase.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the enzyme is a glucose-oxidizing enzyme.
Claim 7
Dependent Claim
90 words
A process for preparing an insoluble but active enzyme, which comprises (a) dissolving a soluble active enzyme in water, (b) treating chitosan to form chitosan sulfate by a method selected from the group consisting of (1) dividing solid chitosan into small pieces of about 10-60 mesh and contacting the pieces with sulfuric acid and (2) dissolving chitosan in water at pH 3-7 and adding thereto a source of sulfate ions, and (c) contacting the chitosan sulfate with the aqueous solution of the enzyme to produce an insoluble but active enzyme.
Claim 8
Dependent Claim
90 words
A process for preparing an insoluble but active enzyme, which comprises (a) dissolving a soluble active enzyme in water, (b) treating chitosan to form chitosan sulfate by a method selected from the group consisting of (1) dividing solid chitosan into small pieces of about 10-60 mesh and contacting the pieces with sulfuric acid and (2) dissolving chitosan in water at pH 3-7 and adding thereto a source of sulfate ions, and (c) contacting the chitosan sulfate with the aqueous solution of the enzyme to produce an insoluble but active enzyme.
Claim 9
Dependent Claim
12 words
The process of claim 6 wherein the enzyme is a sugar-hydrolyzing enzyme.
Claim 10
Dependent Claim
10 words
The process of claim 6 wherein the enzyme is invertase.
Claim 11
Dependent Claim
12 words
The process of claim 6 wherein the enzyme is a glucose-oxidizing enzyme.
References Cited (Backward Citations)
US3909358A
Cited
US4094743A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-10 | 1983-03-12 | 1983-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-10 | 1987-03-12 | 1987-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-10 | 1991-03-12 | 1991-09-11 | $7700.00 | Window Closed / Lapsed |