Albumin formulation and use
The invention relates to a new formulation of albumin, a method for producing the albumin formulation and to uses of the albumin formulation, for example in cell culture such as mammalian cell culture and particularly in stem cell culture.
1. An albumin formulation comprising:
50 to 400 g·L −1 of an albumin or a variant thereof, wherein said albumin consists of the amino acid sequence of SEQ ID NO: 2, and wherein said variant thereof consists of the amino acid sequence of SEQ ID NO: 2 having one or more amino acid substitutions and having at least 98% sequence identity to SEQ ID NO: 2,
a solvent, and,
200 mM or higher concentration of cations,
wherein said formulation has a pH from about 6.0 to about 7.0,
wherein the solvent is inorganic solvent, inorganic buffer, or organic buffer, and
wherein the concentration of octanoate in said formulation is less than or equal to 1 mM octanoate.
2. The albumin formulation according to claim 1 wherein the cations are present at from 200 to 1000 mM.
3. The albumin formulation according to claim 2 wherein the cations are present at from 200 to 350 mM.
4. The albumin formulation according to claim 1 wherein the pH is about pH 6.5.
5. The albumin formulation according to claim 1 wherein the cations are selected from: sodium, potassium, calcium, magnesium, and ammonium.
6. The albumin formulation according to claim 1 wherein the cations are sodium ions.
7. The albumin formulation according to claim 6 which is substantially free of amino acids and/or substantially free of detergent.
8. The albumin formulation according to claim 1 which comprises:
(a) less than 5 mM amino acids; and/or
(b) less than 20 mg·L −1 detergent.
9. The albumin formulation according to claim 1 , wherein the albumin is HSA of SEQ ID NO: 2.
10. The albumin formulation according to claim 1 wherein the albumin is at a concentration of from 50 g·L −1 to 250 g·L −1 .
11. The albumin formulation according to claim 1 wherein the albumin is a recombinant albumin.
12. The albumin formulation according to claim 1 comprising:
(a) 50 to 250 g·L −1 albumin;
(b) 225 to 275 mM Na 30 ;
(c) 20 to 30 mM phosphate;
and having a pH of about 6.5.
13. The albumin formulation according to claim 1 which is substantially free of octanoate.
14. The albumin formulation of claim 1 , wherein the albumin formulation is more stable than a control albumin formulation comprising 150 mM Na.
15. The albumin formulation of claim 1 , wherein said variant has at least 99% sequence identity to SEQ ID NO: 2.
16. The albumin formulation of claim 1 , wherein said variant has one or more point mutations selected from the group consisting of K573P, K573Y, K573W and K500A of SEQ ID NO: 2.
17. A method of culturing cells comprising incubating cells in a culture medium comprising the albumin formulation of claim 1 and a basal medium.
18. The method according to claim 17 in which the cells comprise stem cells.
19. A method of stabilizing albumin or a variant thereof, the method comprising formulating an albumin with a solvent to 50 to 400 g·L −1 , 200 mM or higher concentration of cations, less than or equal to 1 mM octanoate, at a pH from about 6.0 to about 7.0, wherein the solvent is inorganic solvent, inorganic buffer, or organic buffer, wherein the albumin is human serum albumin (HSA) consisting of the amino acid sequence of SEQ ID NO: 2, and wherein said variant thereof consists of the amino acid sequence of SEQ ID NO: 2 having one or more amino acid substitutions and having at least 98% sequence identity to SEQ ID NO: 2.