Streptavidin proteins

• US 20030215922A1
• Filed: 11/01/2002
• Published: 11/20/2003
• Est. Priority Date: 10/21/1991
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Sano, Takeshi, Cantor, Charles R., Glazer, Alexander N.
• Granted Patent: US 7,179,618 B2
• Time in Patent Office: Days
• US Class Current: 435/69.7
• CPC Class Codes: C07H 21/04 with deoxyribosyl as saccharide radical
• CPC Class Codes: C07K 14/36 from Actinomyces; from Streptomyces (G)
• CPC Class Codes: C07K 14/825 Metallothioneins
• CPC Class Codes: C07K 2319/00 Fusion polypeptide
• CPC Class Codes: C07K 2319/22 containing a Strep-tag

Abstract

Streptavidin-metallothionein chimeric proteins with biological recognition specificity in which the streptavidin moiety provides high affinity biotin binding and the metallothionein moiety provides a high affinity metal binding. The binding affinity of the streptavidin-metallothionein chimeric protein both for biotin and heavy metal ions allows specific incorporation into, conjugation with, or labelling of any biological material containing biotin with various heavy metal ions.

Claims

1. A recombinant streptavidin-metallothionein chimeric protein having biological recognition specificity.

2. The protein of claim 1 wherein the encoded streptavidin-metallothionein chimeric protein consists of 190 amino acids.

3. The protein of claim 2 which is expressed in Escherichia coli.

4. The protein of claim 3 which has a 19.5 kDa molecular mass.

5. The protein of claim 4 which is purified to up to 95% homogeneity.

6. The protein of claim 5 containing 10 lysines, 2 histidines, 4 arginines, 10 asparagines, 7 aspartic acids, 24 threonines, 21 serines, 4 glutamic acids, 4 glutamines, 4 prolines, 23 glycines, 20 alanines, 20 cysteines, 10 valines, 2 methionines, 3 isoleucines, 8 leucines, 6 tyrosines, 2 phenylalanines and 6 tryptophanes.

7. An expression vector pTSAMT-2 for the streptavidin-metallothionein chimeric protein constructed from an expression vector pTSA-18F for streptavidin-containing chimeric proteins and a mouse metallothionein-I cDNA.