TABLE 3.
Molecular sizes of fungal and E. coli phytases as determined experimentally or by using the amino acid sequences of the mature proteins
| Source of phytase |
Mr as determined by:
|
Gel filtration analysis
|
Mr as determined by mass spectrometry | ||||
|---|---|---|---|---|---|---|---|
| Sequence analysis | SDS-PAGE | Analytical ultracentrifugation | Mr | Stokes radius (Å) | nc | ||
| A. niger (Natuphos) | 48, 423 | 66,360 ± 2,440 (5)b | 64,890 | 82,360 ± 1,710 | 39.1 ± 0.3 | 4 | NDc |
| A. niger CB | 48,658-48,973 | 74,530 ± 2,800 (5) | 71,020 | 103,030 ± 1,840 | 42.3 ± 0.3 | 4 | ND |
| A. terreus 9A1 | 48,189 | 60,550 ± 1,340 (8) | 70,380 | 79,900 ± 910 | 38.7 ± 0.2 | 3 | ND |
| A. terreus CBSa | 48,570-49,166 | 82,110 ± 720 (3) | 78,030 | 115,100 ± 300 | 43.8 ± 0.1 | 3 | ND |
| A. fumigatus batch 1 | 48,276 | 72,360 ± 520 (5) | 70,740 | 90,500 ± 1,630 | 40.5 ± 0.3 | 4 | |
| A. fumigatus batch 2 | 60,770 ± 2,150 (9) | 62,500-62,800 | |||||
| E. nidulans batch 1 | 49,034-49,360 | 66,430 ± 2,300 (5) | 67,400 | 77,850 ± 600 | 38.4 ± 0.1 | 3 | ND |
| E. nidulans batch 2 | 86,930 ± 1330 | 39.9 ± 0.2 | 3 | ||||
| M. thermophila | 50,524 | 62,890 ± 1,210 (4) | 66,150 | 73,800 ± 200 | 37.6 ± 0.1 | 3 | ND |
| T. thermophilusa | 49,775 | 128,400 ± 1,700 (3) | 137,140 | ND | ND | ND | |
| E. coli | 45,846 | 47,270 ± 60 (3) | 47,060 | 39,190 ± 200 | 28.7 ± 0.1 | 3 | 45,833 |
a
These proteins were expressed in H. polymorpha; all of the other fungal phytases were expressed in A. niger.
b
The numbers in parentheses are the numbers of preparations examined.
c
ND, not determined.