Open AccessCharacterisation of an acid trehalase produced by the thermotolerant fungus Rhizopus microsporus var. rhizopodiformis : Biochemical properties and immunochemical localisation
Author(s) -
Aquino Ana Carla Medeiros Morato,
PeixotoNogueira Simone Carvalho,
Jorge João Atílio,
Terenzi Héctor Francisco,
Polizeli Maria de Lourdes Teixeira de Moraes
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.07.045
Subject(s) - trehalase , fungus , rhizopus , microbiology and biotechnology , rhizopus oryzae , biology , biochemistry , chemistry , enzyme , botany , fermentation
An acid trehalase from Rhizopus microsporus var. rhizopodiformis was purified to apparent homogeneity. The molecular weight by SDS–PAGE (60 kDa) or Sephacryl S‐200 filtration (105 kDa) suggested a homodimer. The carbohydrate content was 72%. Endoglycosidase H digestion resulted in one sharp band of 51.5 kDa in SDS–PAGE. pH and temperature optima were 4.5 and 45 °C, respectively. The isoelectric point was 6.69 and activation energy was 1.14 kcal mol −1 . The enzyme was stable for 1 h at 50 °C and decayed at 60 °C ( t 50 of 1.3 min.). Apparent K M for trealose was 0.2 mM. Immunolocalisation studies showed the enzyme tightly packed at the surface of the cells.