Patent US4814433A successfully refreshed from Google Patents.
US4814433A
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Method for obtaining a papain-free antibody fragment preparation
Assignee: Bayer Corp
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Filing: 1987-09-16
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Granted: 1989-03-21
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Expires: 2007-09-16
Abstract
Abstract A method for obtaining a papain-free F(ab') 2 antibody fragment preparation derived from papain digested whole IgG antibody employing an antibody to papain for binding to and removing papain-associated digestion products from the preparation. The method is particularly useful for digesting whole IgG antibodies which are otherwise sensitive to pepsin digestion to provide F(ab') 2 antibody fragments from which Fab' antibody fragments can be obtained having available free sulfhydryl groups in the hinge region.
Inventors
- 👤 Robert A. Fredrickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:07
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/68; G01N33/6854; G01N33/6857; A; A61; A61K; A61K39/00; A61K39/395; A61K39/39591; Y; Y10; Y10S; Y10S424/00; Y10S424/809; Y10S530/00; Y10S530/866
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
103 words
A method for preparing a papain-free F(ab') 2 antibody fragment preparation derived from papain digested whole IgG antibody, said method comprising the steps of: (a) digesting said whole IgG antibody with papain to produce a digested antibody preparation thereof comprising F(ab') 2 antibody fragments, Fc antibody fragments, papain associated digestion products, and bulk papain; (b) removing said bulk papain from and treating said digested antibody preparation with an antibody to papain whereby said antibody binds to said papain associated digestion products to form antibody-bound species thereof; and (c) separating said F(ab') 2 antibody fragments from said Fc antibody fragments and said antibody-bound species.
Claim 2
Independent Claim
103 words
A method for preparing a papain-free F(ab') 2 antibody fragment preparation derived from papain digested whole IgG antibody, said method comprising the steps of: (a) digesting said whole IgG antibody with papain to produce a digested antibody preparation thereof comprising F(ab') 2 antibody fragments, Fc antibody fragments, papain associated digestion products, and bulk papain; (b) removing said bulk papain from and treating said digested antibody preparation with an antibody to papain whereby said antibody binds to said papain associated digestion products to form antibody-bound species thereof; and (c) separating said F(ab') 2 antibody fragments from said Fc antibody fragments and said antibody-bound species.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said bulk papain is removed by binding to said antibody to papain to form antibody-bound species thereof.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein said bulk papain is removed prior to treating said digested antibody preparation with said antibody to papain.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein said bulk papain is removed by gel filtration.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein said papain is activated with a reducing agent selected from the group consisting of cysteine, β-mercaptoethanol, dithiothreitol and mercaptoethylamine.
Claim 7
Dependent Claim
21 words
The method of claim 1 further comprising the step of reducing said F(ab') 2 antibody fragments to Fab' antibody fragments thereof.
Claim 8
Dependent Claim
21 words
The method of claim 6 wherein said reducing agent is selected from the group consisting of cysteine, dithiothreitol, β-mercaptoethanol, and mercaptoethylamine.
Claim 9
Dependent Claim
48 words
The method of claim 1 wherein said antibody-bound species and said Fc antibody fragment of step (b) are separated with an immobilized form of a specific binding substance for said papain antibody and said Fc antibody fragment whereby said antibody-bound species and said Fc fragment are immobilized thereto.
Claim 10
Dependent Claim
27 words
The method of claim 8 wherein said immobilized form of said specific binding substance for said antibody to papain and said Fc antibody fragment is protein A.
Claim 11
Dependent Claim
15 words
The method of claim 1 wherein said whole IgG antibody is a monoclonal IgG antibody.
Claim 12
Dependent Claim
16 words
A papain-free F(ab') 2 divalent antibody fragment preparation prepared according to the method of claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |