Human alpha-galactosidase variants
The present invention provides engineered human alpha-galactosidase polypeptides and compositions thereof. The engineered human alpha-galactosidase polypeptides have been optimized to provide improved stability under both acidic (pH<4.5) and basic (pH>7) conditions. The invention also relates to the use of the compositions comprising the engineered human alpha-galactosidase polypeptides for therapeutic purposes.
1. A recombinant polynucleotide sequence encoding an alpha galactosidase A comprising an amino acid sequence comprising at least 95%, sequence identity to SEQ ID NO: 5, wherein said amino acid sequence comprises a substitution at amino acid position 206 compared to SEQ ID NO:5, and wherein said positions are numbered with reference to SEQ ID NO: 5.
2. The recombinant polynucleotide of claim 1 , wherein said substitution at amino acid position 206 is selected from 206A, 206M, 206Q, 206R, 206T, 206E, 206G and 206S.
3. The recombinant polynucleotide sequence of claim 1 , wherein said encoded recombinant alpha galactosidase A exhibits at least one improved property selected from: i) increased thermostability; ii) enhanced catalytic activity; iii) increased tolerance to pH 7.4; iv) increased tolerance to pH 4.3; v) increased tolerance to serum; or vi) reduced immunogenicity; or a combination of any of i), ii), iii), iv), v), or vi), as compared to a reference alpha galactosidase A.
4. The recombinant polynucleotide sequence of claim 3 , wherein said encoded recombinant alpha galactosidase A is more thermostable than the alpha galactosidase A of SEQ ID NO:5.
5. The recombinant polynucleotide sequence of claim 3 , wherein said encoded recombinant alpha galactosidase A is more stable at pH 7.4 than the alpha galactosidase A of SEQ ID NO:5.
6. The recombinant polynucleotide sequence of claim 3 , wherein said encoded recombinant alpha galactosidase A is more stable at pH 4.3 than the alpha galactosidase A of SEQ ID NO:5.
7. The recombinant polynucleotide sequence of claim 3 , wherein said encoded recombinant alpha galactosidase A is more stable to exposure to serum than the alpha galactosidase A of SEQ ID NO:5.
8. The recombinant polynucleotide sequence of claim 3 , wherein said encoded recombinant alpha galactosidase A is less immunogenic than wild-type alpha galactosidase A.
9. The recombinant polynucleotide sequence of claim 1 , wherein the polypeptide of said encoded recombinant alpha galactosidase A further comprises at least one substitution compared to SEQ ID NO:5 at a position selected from position 2, 7, 8, 10, 14, 15, 17, 20, 21, 23, 24, 30, 31, 34, 36, 37, 39, 40, 41, 43, 44, 47, 48, 52, 53, 56, 59, 64, 65, 66, 67, 74, 76, 77, 80, 84, 87, 88, 91, 92, 93, 94, 95, 96, 100, 102, 105, 113, 120, 123, 124, 125, 130, 133, 136, 143, 144, 147, 155, 156, 158, 159, 160, 161, 162, 163, 165, 166, 167, 168, 169, 170, 174, 177, 178, 179, 180, 181, 182, 186, 187, 189, 190, 195, 198, 199, 208, 210, 217, 219, 221, 228, 230, 234, 237, 238, 246, 247, 249, 252, 253, 254, 255, 256, 257, 258, 259, 261, 262, 263, 266, 269, 270, 271, 273, 274, 276, 277, 281, 283, 284, 287, 290, 293, 295, 299, 301, 302, 303, 305, 308, 314, 316, 317, 319, 322, 325, 326, 337, 339, 343, 344, 345, 346, 348, 349, 350, 352, 353, 354, 359, 362, 365, 367, 368, 369, 371, 373, 374, 375, 376, 377, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, and 398, wherein the positions are numbered relative to SEQ ID NO: 5.
10. The recombinant polynucleotide sequence of claim 1 , wherein said polynucleotide sequence is codon-optimized.
11. An expression vector comprising the recombinant polynucleotide sequence of claim 10 .
12. The expression vector of claim 11 , wherein said recombinant polynucleotide sequence is operably linked to a control sequence.
13. The expression vector of claim 12 , wherein said control sequence is a promoter.
14. The expression vector of claim 13 , wherein said promoter is a heterologous promoter.
15. A host cell comprising the expression vector of claim 13 .
16. A host cell comprising the expression vector of claim 14 .
17. The host cell of claim 13 , wherein said host cell is eukaryotic.
18. A method of producing an alpha galactosidase A variant, comprising culturing said host cell of claim 15 , under conditions that said alpha galactosidase A variant encoded by said recombinant polynucleotide is produced.
19. The method of claim 18 , further comprising the step of recovering said alpha galactosidase A variant.
20. The method of claim 19 , further comprising the step of purifying said alpha galactosidase A variant.