US4609627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Enzymatic conversion of certain sub-type A and AB erythrocytes
Assignee: New York Blood Center
•
Filing: 1983-08-01
•
Granted: 1986-09-02
•
Expires: 2003-08-01
Abstract
Abstract Type O erythrocytes are produced from certain subtypes of A erythrocytes or type AB erythrocytes by contacting the same following equilibration of a pH of 5.6-5.8 with an alpha -N-acetylgalactosaminidase, preferably obtained from an avian liver, for periods sufficient to convert the A antigen in the erythrocyte to the H antigen. Following removal of the enzyme, the erythrocyte is re-equilibrated to a pH of 7.2-7.4. As a result, there is obtained O type erythrocytes characterized by a 60 to 90 percent ATP level based on the level of ATP in naturally occurring O or AB erythrocytes. Beginning with certain A cells one obtains synthetic O erythrocytes characterized by a terminal alpha -fucose moiety, O antigenicity, and the absence of A antigenicity. Beginning with A2B erythrocytes, one obtains B erythrocytes by the same process characterized by the absence of A antigenicity, greater H antigenicity than naturally occurring A2B cells, the presence of B antigenicity and the aforedescribed ATP levels.
Inventors
- 👤 Jack Goldstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:26
CPC Classifications
A; A61; A61K; A61K35/00; A61K35/12; A61K35/14; A61K35/18; A61P; A61P7/00; A61P7/08
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
108 words
A composition comprising type B erythrocytes, said erythrocytes characterized by (a) the absence of A antigenicity, (b) greater H antigenicity than naturally occurring A 2 B cells, (c) presence of B antigenicity and (d) 60-90% of the adenosine-5'-triphosphate (ATP) content of naturally occurring A 2 B erythrocytes, said composition produced by (i) equilibrating A 2 B erythrocytes to a pH of 5.6 to 5.8; (ii) thereafter contacting the so-equilibrated erythrocytes with an alpha-N-acetylgalactosaminidase enzyme for a period sufficient to convert the A antigen in said erythrocyte to the H-antigen; (iii) removing said enzyme from said erythrocytes; and (iv) re-equilibrating said erythrocytes to a pH of 7.2 to 7.4.
Claim 2
Dependent Claim
108 words
A composition comprising type B erythrocytes, said erythrocytes characterized by (a) the absence of A antigenicity, (b) greater H antigenicity than naturally occurring A 2 B cells, (c) presence of B antigenicity and (d) 60-90% of the adenosine-5'-triphosphate (ATP) content of naturally occurring A 2 B erythrocytes, said composition produced by (i) equilibrating A 2 B erythrocytes to a pH of 5.6 to 5.8; (ii) thereafter contacting the so-equilibrated erythrocytes with an alpha-N-acetylgalactosaminidase enzyme for a period sufficient to convert the A antigen in said erythrocyte to the H-antigen; (iii) removing said enzyme from said erythrocytes; and (iv) re-equilibrating said erythrocytes to a pH of 7.2 to 7.4.
Claim 3
Dependent Claim
24 words
A composition according to claim 1, wherein said erythrocytes have a 2,3-diphosphoglyceric acid (2,3-DPG) level of 60-90% of naturally occurring A 2 B erythrocytes.
Claim 4
Dependent Claim
21 words
A composition according to claim 2, wherein said erythrocytes have a met-hemoglobin level of 2-6% of total hemoglobin in the erythrocytes.
Claim 5
Dependent Claim
22 words
A composition according to claim 3, wherein said erythrocytes have 70-90% of the ATP content of naturally occurring A 2 B erythrocytes.
Claim 6
Dependent Claim
22 words
A composition according to claim 3, wherein said erythrocytes have 80-90% of the ATP content of naturally occurring A 2 B erythrocytes.
Claim 7
Dependent Claim
24 words
A composition according to claim 1, wherein said B erythrocytes have at least 20% greater H antigenicity than naturally occurring A 2 B cells.
Claim 8
Dependent Claim
143 words
A composition comprising type B erythrocytes, said erythrocytes characterized by (a) the absence of A antigenicity, (b) at least 20% greater H antigenicity than naturally occurring A 2 B cells, (c) presence of B antigenicity, (d) 70 to 90% of the adenosine-5'-triphosphate (ATP) content of naturally occurring A 2 B erythrocytes, (e) 80 to 90% of the 2,3-diphosphoglyceric acid (2,3 DPG) level of naturally occurring A 2 B erythrocytes, and (f) a met-hemoglobin level of 2-6% of total hemoglobin in the erythrocytes, said composition produced by (i) equilibrating A 2 B erythrocytes to a pH of 5.6 to 5.8; (ii) thereafter contacting the so-equilibrated erythrocytes with an alpha-N-acetylgalactosaminidase enzyme for a period sufficient to convert the A antigen in said erythrocyte to the H-antigen; (iii) removing said enzyme from said erythrocytes; and (iv) re-equilibrating said erythrocytes to a pH of 7.2 to 7.4.
Claim 9
Dependent Claim
143 words
A composition comprising type B erythrocytes, said erythrocytes characterized by (a) the absence of A antigenicity, (b) at least 20% greater H antigenicity than naturally occurring A 2 B cells, (c) presence of B antigenicity, (d) 70 to 90% of the adenosine-5'-triphosphate (ATP) content of naturally occurring A 2 B erythrocytes, (e) 80 to 90% of the 2,3-diphosphoglyceric acid (2,3 DPG) level of naturally occurring A 2 B erythrocytes, and (f) a met-hemoglobin level of 2-6% of total hemoglobin in the erythrocytes, said composition produced by (i) equilibrating A 2 B erythrocytes to a pH of 5.6 to 5.8; (ii) thereafter contacting the so-equilibrated erythrocytes with an alpha-N-acetylgalactosaminidase enzyme for a period sufficient to convert the A antigen in said erythrocyte to the H-antigen; (iii) removing said enzyme from said erythrocytes; and (iv) re-equilibrating said erythrocytes to a pH of 7.2 to 7.4.
Claim 10
Dependent Claim
73 words
A process for converting A int -A 2 including A 2 B erythrocytes to erythrocytes of the H antigen type which comprises: (a) equilibrating said erythrocytes to a pH of 5.6-5.8; (b) thereafter contacting the so-equilibrated erythrocytes with an α-N-acetylgalactosaminidase enzyme for a period sufficient to convert the A antigen in said erythrocyte to the H-antigen; (c) removing said enzyme from said erythrocytes; and (d) re-equilibrating said erythrocytes to a pH of 7.2-7.4.
Claim 11
Dependent Claim
73 words
A process for converting A int -A 2 including A 2 B erythrocytes to erythrocytes of the H antigen type which comprises: (a) equilibrating said erythrocytes to a pH of 5.6-5.8; (b) thereafter contacting the so-equilibrated erythrocytes with an α-N-acetylgalactosaminidase enzyme for a period sufficient to convert the A antigen in said erythrocyte to the H-antigen; (c) removing said enzyme from said erythrocytes; and (d) re-equilibrating said erythrocytes to a pH of 7.2-7.4.
Claim 12
Dependent Claim
16 words
A process according to claim 8, wherein said N-acetylglactosaminidase is one obtained from an avian liver.
Claim 13
Dependent Claim
23 words
A process according to claim 9, wherein said N-acetylgalactosaminidase has 3-4 enzyme units per ml of protein at pH 5.7 and 32° C.
Claim 14
Dependent Claim
15 words
A process according to claim 9, wherein said enzyme is in the free enzyme form.
Claim 15
Dependent Claim
26 words
A process according to claim 9, wherein A int -A 2 cells which are not in the B form are converted to the H antigen form.
Claim 16
Dependent Claim
26 words
A process according to claim 9, wherein said α-N-acetylgalactosaminidase has an enzyme activity of 24-30 units per ml at pH of 4 and at 37° C.
Claim 17
Dependent Claim
21 words
A process according to claim 3, wherein said enzyme has an isoelectric point at 4° C. of between 7.5 and 7.8.
Claim 18
Dependent Claim
15 words
A process according to claim 9, wherein said enzyme is in a supported form. pg,35
Claim 19
Dependent Claim
13 words
A process according to claim 15, wherein said support is a soluble support.
Claim 20
Dependent Claim
13 words
A process according to claim 15, wherein said support is an insoluble support.
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) | 1989-09-01 | 1990-03-03 | 1990-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-01 | 1994-03-03 | 1994-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |