Metalloprotein compositions

Patent metadata

Field	Value
Publication number	US-10870875-B2
Application number	US-201515527266-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Nov 17, 2014
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

The present invention relates to compositions comprising: a polypeptide, wherein at least a portion of the polypeptide has a coiled coil structure; and a chelate comprising a chelating agent and a metal ion; and wherein the chelate is bound to at least one amino acid of the polypeptide. In a preferred embodiment the polypeptide is a silk fibroin, wherein at least a portion of the silk fibroin has a coiled coil structure.

First claim

The invention claimed is:

1. A composition comprising:
a silk polypeptide wherein at least a portion of the silk polypeptide has a coiled coil structure, wherein the silk polypeptide comprises at least 5 copies of the heptad sequence abcdefg, and wherein at least 15% of the amino acids at position a in the heptad repeats are alanine; and
a chelate comprising a chelating agent and a metal ion; and
wherein the chelate is bound to at least one amino acid of the silk polypeptide.

2. A composition of claim 1 , wherein the chelating agent is bound to at least one amino acid of the silk polypeptide via electrostatic interactions.

3. A composition of claim 1 , wherein the metal ion is bonded to at least one amino acid of the silk polypeptide by a co-ordinate bond.

4. A composition of claim 1 consisting of the silk polypeptide and the chelate.

5. A composition of claim 1 , wherein the silk polypeptide comprises about 9 to about 30 heptad repeats.

6. A composition of claim 5 , wherein the silk polypeptide comprises about 22 to about 28 heptad repeats.

7. A composition of claim 3 , wherein the at least one amino acid bound to the metal ion by a co-ordinate bond is a Tyr, Cys, His, Met, Lys, Glu or a non-natural amino acid.

8. A composition of claim 1 , wherein at least one amino acid residue bound to the chelating agent is a charged amino acid residue.

9. A composition of claim 1 , wherein the chelating agent is selected from the group consisting of porphryins, corrins, chlorins, corphins, porphines and phthalocyanines.

10. A composition of claim 1 , wherein the metal ion is an ion of a transition metal, alkali earth metal or p-block metal.

11. A composition of claim 1 , wherein the composition is capable of binding a target compound.

12. A material comprising a composition of claim 1 , wherein the composition comprises a plurality of the silk polypeptides which are crosslinked by ionic bonds, hydrogen bonds, covalent bonds or a combination thereof and the material is insoluble in water.

13. A sensor for detecting a target compound comprising a composition of claim 1 .

14. A sensor of claim 13 , wherein the target compound is selected from the group consisting of oxygen, carbon monoxide, carbon dioxide, compounds having an atom of P, S, or N, and mixtures thereof.

15. A sensor of claim 14 , wherein the target compound is NO.

16. A sensor of claim 14 , wherein the target compound is oxygen.

17. A sensor of claim 13 , wherein binding of the target compound to the sensor results in a detectable change selected from colour, spectrophotometric, fluorescent or electrochemical change.

18. A sensor of claim 17 , wherein the spectrophotometric change is a change in the Soret peak, or a change in at least one spectrophotometric peak with a wavelength between 500 and 600 nm.

19. A method of detecting a target compound, said method comprising the steps of
(a) providing a sensor of claim 13 , and
(b) contacting the sensor with a target compound under conditions for binding said compound to said sensor.

20. The method of claim 19 which further comprises detecting binding of the target compound by detecting a change in the sensor upon binding to the target compound.

21. The composition of claim 1 , wherein at least 25% of the amino acids at position a in the heptad repeats are alanine.

22. The composition of claim 1 , wherein 30% to 70% of the amino acids at position a in the heptad repeats are alanine.

23. The composition of claim 1 , wherein at least 25% of the amino acids at positions a and d are alanine residues.

Assignees

• Commw Scient Ind Res Org

Inventors

• Sutherland Tara
• Rapson Trevor

Classifications

• G01N21/783

  for analysing gases · CPC title

• G01N31/225

  for oxygen, e.g. including dissolved oxygen · CPC title

• C12Q1/005

  involving specific analytes or enzymes (including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence) · CPC title

• G01N31/224

  for investigating presence of dangerous gases · CPC title

• C12Q1/28

  involving peroxidase · CPC title