Patent US5235041A successfully refreshed from Google Patents.
US5235041A
Expired / Lapsed
US
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Purification of structurally ordered recombinant protein polymers
Assignee: Protein Polymer Technologies Inc
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Filing: 1992-04-13
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Granted: 1993-08-10
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Expires: 2012-04-13
Abstract
Abstract Recombinant structural and functional polymers are purified by lysing of the cellular host, separation of the solid materials, washing and extraction of contaminants using a detergent solution at elevated temperatures.
Inventors
- 👤 Joseph Cappello
- 👤 Franco A. Ferrari
- 👤 Tina L. Buerkle
- 👤 Garret Textor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:51
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/435; C07K1/00; C07K1/14; C07K1/36; C07K14/78
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
113 words
A method of purification of substantially insoluble protein polymers, said polymers being characterized by being prepared by recombinant techniques, having long stretches of repeating units of silk fibroin and sufficient stretches of the repeating units so that the polymers have the structural order of silk, said method comprising: treating and lysing cells to provide lysate comprising said protein polymers in insoluble form; suspending the disrupted cells from said lysate in an aqueous medium; separating high molecular weight insoluble material from the suspension; extracting said separated high molecular weight insoluble material at a temperature in the range of about 60° to 100° C. with an aqueous detergent solution; and isolating the purified protein polymer.
Claim 2
Independent Claim
113 words
A method of purification of substantially insoluble protein polymers, said polymers being characterized by being prepared by recombinant techniques, having long stretches of repeating units of silk fibroin and sufficient stretches of the repeating units so that the polymers have the structural order of silk, said method comprising: treating and lysing cells to provide lysate comprising said protein polymers in insoluble form; suspending the disrupted cells from said lysate in an aqueous medium; separating high molecular weight insoluble material from the suspension; extracting said separated high molecular weight insoluble material at a temperature in the range of about 60° to 100° C. with an aqueous detergent solution; and isolating the purified protein polymer.
Claim 3
Dependent Claim
16 words
A method according to claim 1, wherein lysing comprises mechanical disruption and said separating comprises centrifugation.
Claim 4
Dependent Claim
27 words
A method according to claim 1, wherein said extracting is performed at a temperature of at least about 80° C. and said detergent solution is sodium dodecylsulfate.
Claim 5
Dependent Claim
12 words
A method according to claim 1, wherein said isolating is by centrifugation.
Claim 6
Independent Claim
130 words
A method of purification of substantially insoluble protein polymers, said polymers being characterized by being prepared by recombinant techniques, having long stretches of silk fibroin repeating units and having sufficient stretches of the repeating units so that the polymers have the structural order of silk, said method comprising: treating and lysing cells comprising said protein polymers by mechanical disruption to provide lysate comprising said protein polymers in insoluble form; separating high molecular weight insoluble material from said lysate by means of centrifugation; extracting said separated high molecular weight insoluble material at a temperature in the range of about 80° to 100° C. with an aqueous anionic sulfuric acid based detergent solution, said detergent being present in from about 1 to 3% w/v; and isolating the purified protein polymer by centrifugation.
Claim 7
Independent Claim
130 words
A method of purification of substantially insoluble protein polymers, said polymers being characterized by being prepared by recombinant techniques, having long stretches of silk fibroin repeating units and having sufficient stretches of the repeating units so that the polymers have the structural order of silk, said method comprising: treating and lysing cells comprising said protein polymers by mechanical disruption to provide lysate comprising said protein polymers in insoluble form; separating high molecular weight insoluble material from said lysate by means of centrifugation; extracting said separated high molecular weight insoluble material at a temperature in the range of about 80° to 100° C. with an aqueous anionic sulfuric acid based detergent solution, said detergent being present in from about 1 to 3% w/v; and isolating the purified protein polymer by centrifugation.
Claim 8
Dependent Claim
20 words
A method according to claim 5, wherein said aqueous anionic sulfuric acid based detergent solution is 1.5 to 3% w/v.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |