Method for recombinant microorganism expression and isolation of collagen-like polypeptides

4) An emulsion according to any of the preceding claims said peptizer having an amino acid sequence equivalent to that occurring in nature for collagen, wherein equivalent implies amino acid identity of at least 80%, preferably at least 90%, most preferably with an amino acid sequence the same as occurs in nature.

5) An emulsion according to any of the preceding claims, wherein the peptizer has an amino acid sequence substantially the same as occurs in nature, wherein substantially implies mutation of less than 5 amino acids, preferably less than 3.

6) An emulsion according to any of the preceding claims, wherein the peptizer is substantially pure collagen like material prepared by native collagen encoding nucleic acid.

7) An emulsion according to any of the preceding claims, wherein the peptizer has an amino acid sequence substantially the same as occurs in nature for collagen type I, II or III.

8) An emulsion according to any of the preceding claims, wherein the peptizer has an amino acid sequence equivalent to the amino acid sequence occurring in nature for collagen type I, II or III.

9) An emulsion according to any of the preceding claims, wherein the peptizer has an amino acid sequence the same as occurs in nature for collagen type I, II or III.

10) An emulsion according to any of the preceding claims, wherein the collagen type I comprises or has the amino acid sequence of FIGS. 8, 10 or 12 or Genbank accession number U08020.

12) An emulsion according to any preceding claim, said peptizer having an amino acid sequence substantially the same as occurs in nature for collagen type I, the peptizer being free of a sequence [MLIV]XXR and preferably free of MGPR.

13) An emulsion according to any of the preceding claims, wherein the peptizer is a fragment of defined length and composition derived from a native collagen encoding sequence, said fragment comprising the GXY motif characteristic of collagen, said length being such that the fragment weight on amino acid basis is at least 2.5 kDa.

14) An emulsion according to any of the preceding claims, wherein the peptizer is free of hydroxyproline.

15) An emulsion according to any of the preceding claims, wherein the peptizer is not deaminated.

16) An emulsion according to any of the preceding claims, wherein the peptizer has an isoelectric point of 7-10.

17) An emulsion according to any of the preceding claims, wherein the peptizer has a weight on amino acid basis of 2.5-100 kDa.

18) An emulsion according to any of the preceding claims, said peptizer being free of procollagen and telopeptides.

19) An emulsion according to any of the preceding claims, said peptizer being free of helix structure.

20) An emulsion according to any of the preceding claims, said peptizer being free of cysteine.

21) An emulsion according to any of the preceding claims, said peptizer comprising (oxidated) reducing amino acids to a degree that reducing amino acids methionine and histidine are present at a level equivalent to a reducing strength of between 0.1-200, preferably between 0.1-120 micromoles of methionine per gram of said peptizer.

22) An emulsion according to any of the preceding claims, said peptizer comprising (oxidated) reducing amino acids to a degree that reducing amino acids are present at a level equivalent to a reducing strength of between 0.1-80 micromoles of methionine per gram of said peptizer.

23) An emulsion according to any of the preceding claims, said peptizer comprising (oxidated) reducing amino acids to a degree that reducing amino acids are present at a level equivalent to a reducing strength of between 30-80 micromoles of methionine per gram of said peptizer.

24) An emulsion according to any of the preceding claims, said peptizer having a binding strength for silver higher than 50 mV,

25) An emulsion according to any of the preceding claims, said peptizer having a binding strength for silver below 100 mV,

26) An emulsion according to any of the preceding claims, said peptizer having a binding strength for silver between 50-100 mV.

27) An emulsion according to any of the preceding claims, wherein the silver halide grains exhibit an average aspect ratio higher than 5.

28) An emulsion according to any of the preceding claims, wherein the peptizer is stable vis a vis silver halide tabular grain formation at a pH between 4-8.

29) An emulsion according to any of the preceding claims comprising tabular grains at a level more than 90%, preferably more than 95%

30) An emulsion according to any of the preceding claims wherein the peptizer is of a homo disperse nature.

31) An emulsion according to any of the preceding claims wherein the peptizer is present in substantially pure form i.e. substantially free of nucleic acid, polysaccharides and other protein.

32) An emulsion according to any of the preceding claims, said emulsion being suitable for photographic application and comprising further compounds acceptable for such application, e.g. a second clearly defined amount of growth peptizer.

33) A process of preparing tabular silver halide emulsion wherein the tabular grains account for more than 75% of the total grain projected area said process comprising nucleation of silver halide grains in the presence of nucleation peptizer and thereafter growing said silver halide grains in the presence of growth peptizer, wherein both peptizers are present in a defined amount and at least one peptizer is collagen like material prepared by genetic engineering, said peptizers having an amino acid sequence comprising more than 4 different amino acids.

34) A process for preparing an emulsion according to claim 33 comprising addition of the peptizer in the nucleation step and/or during the grain growing step, said peptizer being selected from any of the embodiments disclosed in any of claims 1-32, 52 or 53.

40) A process of producing recombinant collagen like polypeptide comprising expression of a collagen like polypeptide encoding nucleic acid sequence by a microorganism to a degree exceeding 0.95 gram liter, said recombinant collagen being free of helix structure and preferably the expression occurring in a microorganism other than E. coli or Saccharomyces cerevisiae.

42) A process according to claim 40 or 41 wherein the recombinant collagen like peptide is selected from any of the embodiments disclosed in any of claims 1-32, 52 or 53.

52) A substantially pure collagen like material prepared by genetic engineering, said peptizer having an amino acid sequence exhibiting more than 40% homology with native collagen and comprising more than 4 different amino acid types.