Table 4.
Resistance to thermal inactivation (T 50) and apparent melting temperatures of various CGTases
| Enzyme | Interactions | T 50 for β-cyclization activity (°C) | Apparent melting | |
|---|---|---|---|---|
| Ionic | Disulfide bonds | DSC (°C) | ||
| Tabium | 57 | 0 | 94.5 | 96.9 |
| B. circulans strain no. 8 | 53 | 1 | 62.9 | 67.1 |
| B. circulans strain 251 | 58 | 1 | 66.1 | 69.1 |
| B. stearothermophilus NO2 | 67 | 1 | 80.9 | nd |
| Novamyl | 66 | 0 | 88a | 88.8 |
| Alkalophilic Bacillus sp. 1011b | 55 | 1 | –b | –b |
| Toruzyme | nc | nc | 97.8 | nc |
| Bacillus sp. strain A2-5a | nc | nc | 64.6 | 69 |
| Anaerobranca gottschalkii | nc | nc | 63.3 | 67.2 |
| Klebsiella pneumoniae | nc | nc | 47.2 | nc |
| Thermococcus sp. B1001 | nc | nc | nd | 106c |
Also structural factors possibly contributing to thermostability is given for CGTases with known 3D structure
nc 3D structure has not been solved, nd not determined
a(Beier et al. 2000). The T 50 value of Novamyl was determined by measuring residual starch hydrolyzing activity
bThis CGTase was not investigated in this study
c(Yamamoto et al. 1999)