Transglutaminase originating from Crassostrea gigas

• US 5,736,356 A
• Filed: 09/28/1995
• Issued: 04/07/1998
• Est. Priority Date: 01/28/1994
• Status: Expired due to Term

• Current Assignee: Ajinomoto Co., Inc.
• Original Assignee: Ajinomoto Co., Inc.
• Inventors: Sano, Kohichiro, Yasueda, Hisashi, Seguro, Katsuya, Kumazawa, Yoshiyuki, Motoki, Masao
• Primary Examiner(s): Patterson, Jr., Charles L.
• Assistant Examiner(s): Bugaisky, Gabriele E.
• Application Number:
  US08/525,654
• Time in Patent Office: 922 Days
• Field of Search: 435/193, 435/172.3, 435/320.1, 435/252.3, 435/252.33, 435/254.11, 435/68.1, 435/254.21, 435/325, 536/23.2, 426/573
• US Class Current: 435/68.1
• CPC Class Codes: C12N 9/1044 Protein-glutamine gamma-glutamyltransferase (2.3.2.13), i.e. transglutaminase or factor XIII

Abstract

The present invention relates to a transglutaminase originating from Crassostrea gigas, a gene coding for the transglutaminase, a plasmid carrying the gene, a microorganism transformed with the plasmid, a method for producing an intended transglutaminase by cultivating the microorganism and a method for gelating a protein using the transglutaminase originating from Crassostrea gigas. When comparing with other transglutaminases, the transglutaminase originating from Crassostrea gigas has novel characteristic properties such that it can be activated by the action of calcium ions and that it is further activated by the addition of sodium chloride and/or potassium chloride and it is of utility value, in particular, as a gelling agent for foods.

Claims

1. A transglutaminase enzyme originating from Crassostrea gigas having the following characteristics:

a) substrate specificity in which said enzyme catalyzes the transfer of an acyl group between primary amines and γ

-carboxyamide groups of accessible glutamine residues present in a protein or a polypeptide chain;

b) molecular weight as determined by SDS-PAGE is about 83,000 to 95,000 Da;

c) optimal temperature range of 30°

C. to 50°

;

d) optimal pH range of about 7.5 to 9.5;

e) activation by calcium ions with further enhancement of activity by NaCl or KCl; and

f) inhibition by N-ethylmaleimide, monoiodo acetic acid, p-chloromercuribenzoic acid or Cu²⁺.

2. The transglutaminase of claim 1 which comprises an amino acid sequence of SEQ ID NO:

141 or 142.

3. A purified and isolated gene encoding the Crassostrea gigas transglutaminase enzyme of claim 1.

4. The gene of claim 3 which has a sequence encoding SEQ ID NO:

1.

5. The gene of claim 3 which has a sequence encoding SEQ ID NO:

3.

6. The gene of claim 3 which has the sequence of SEQ ID NO:

2.

7. The gene of claim 3 which has the sequence of SEQ ID NO:

4.

8. The gene of claim 3 which hybridizes to the complement of the strand of a) the DNA encoding SEQ ID NO:

1 or 3, or b)DNA having SEQ ID NO;

2 or 4 and encodes an enzyme having the same activity as the transglutaminase of claim 1.

9. A plasmid containing the gene of claim 3.

10. An isolated cell transformed with the plasmid of claim 9.

11. The cell of claim 10 which is Escherichia coil or Saccharomyces cerevisiae.

12. A method for obtaining a transglutaminase originating from Crassostrea gigas comprising the steps of cultivating the transformed cell of claim 10 to produce the enzyme and isolating it from the medium.

13. A transglutaminase originating from Crassostrea gigas prepared by the method of claim 12.

15. The gelling agent of claim 14 wherein the transglutaminase originating from Crassostrea gigas is that set forth in claim 1.

16. The gelling agent of claim 14 wherein the transglutaminase originating from Crassostrea gigas is that set forth in claim 13.

18. The gelling method of claim 17 wherein the transglutaminase originating from Crassostrea gigas is that set forth in claim 1.

19. The gelling method of claim 17, wherein the transglutaminase originating from Crassostrea gigas is that set forth in claim 13.

14. A gelling agent comprising a transglutaminase originating from Crassostrea gigas.

17. A method for gelating a protein comprising treating a protein solution or slurry having a concentration of not less than 0.1% by weight with a transglutaminase originating from Crassostrea gigas for a time sufficient to convert the solution or slurry into a gel.

20. The gelling method of claim 17, wherein the gelation of the protein solution or slurry is controlled by adjusting the concentration of a salt.

21. The gelling method of claim 20, wherein the salt is NaCl or KCl.

22. The gelling method of claim 17, wherein the gelation of the protein solution or slurry is controlled by adjusting the concentration of calcium ions.