TABLE 4.
Ratio of reaction products generated from mannohexaose
| Enzyme | Ratio (M2 + M4)/M3a |
|---|---|
| Man26C wild type | 1:0 |
| Man26A wild type | 2.2:1 |
| Man26C L129G | 1:0 |
| Man26C L129A | 1:0 |
| Man26C D130G | 3.8:1 |
| Man26C D130A | 3.0:1 |
| Man26C L129G/D130G | 1:0 |
| Man26C L129A/D130A | 5.6:1 |
| Man26C ΔL129/D130 | 4.2:1 |
| Man26C ΔN128/L129/D130 | 2.1:1 |
| Man26C ΔN128/L129/D130/A131 | 2.3:1 |
a
The ratio of products was measured after 30% hydrolysis of 30 μM mannohexaose. A completely exo-acting enzyme will generate only mannobiose from mannohexaose; hence, a ratio of 1:0 is observed for wild type CjMan26C and three of the exo-acting mutants. A fully endo-acting mannanase, exemplified by CjMan26A, has a ratio of 2:1 ((mannobiose and mannotetraose)/mannotriose), similar to three of the mutants. A ratio higher ratio than 2:1, observed for four of the mutants, indicates an endo-activity, but substrate binding to the different subsites is not completely random.