TABLE 2.
Biochemical properties of isolated holo- and apocatalase and catalase assembled in vitro at two different temperatures
Data presented are the result from at least three independent preparations. Heme was determined by the pyridine hemochromogen procedure assuming 1 mol of protoheme IX per mol of KatA in isolated holocatalase. One unit (U) is 1 μmol of H2O2 degraded per min at the assay conditions used (see “Experimental procedures” for details). Numbers within parentheses show relative activities.
| Holocatalase | Apocatalase |
In vitro assembled catalase |
||
|---|---|---|---|---|
| at 15 °C | at 37 °C | |||
| Protoheme IX/KatA (mol/mol) | 1 | <0.05 | 0.9 ± 0.1 | 0.8 ± 0.1 |
| Catalase activity (U/pmol KatA) | 4.2 ± 1.0 (100%) | <0.01 (<0.2%) | 3.9 ± 2.0 (∼93%) | 0.26 ± 0.05 (∼6%) |