Physicochemical properties of -galactosidase

Physicochemical properties of P-galactosidase Native BGase, a tetramer, has a molecular weight of 465000 (from its complete amino acid sequence) and a pi of 4.6 (Fowler and Zabin, 1977). The tetramer dissociates into inactive monomers at pH 3.5 or 11.5 or with mercurials (Loontiens et al., 1970). Aggregated 

The enzyme is stable for at least 30 min at 40 C within pH 6-8 (Wallenfels and Weil, 1972), but its stability at 40°C falls sharply below pH 6.0 and slowly above pH 8.0. Heat stability is considerably lowered by various intermediates in the glucose metabolic cycle (Brewer and Moses, 1967). 

It is of interest for EIA that BGase is an excellent immunogen, that anti-BGase antibodies do not inhibit enzymic activity (Cohn and Torriani, 1952) and that some inactive BGase mutants can be activated through the reaction with specific antibodies (Rotman and Celada, 1968). 

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