Characterisation of an acid trehalase produced by the thermotolerant fungus Rhizopus microsporus var. rhizopodiformis: biochemical properties and immunochemical localisation.
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 degrees 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 degrees C and decayed at 60 degrees C (t50 of 1.3 min.). Apparent KM for trealose was 0.2mM. Immunolocalisation studies showed the enzyme tightly packed at the surface of the cells.
de Aquino
Ana Carla Medeiros Morato
AC
Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14.040-901 Ribeirão Preto, SP, Brazil.
Peixoto-Nogueira
Simone Carvalho
SC
Jorge
João Atílio
JA
Terenzi
Héctor Francisco
HF
Polizeli
Maria de Lourdes Teixeira de Moraes
Mde L
D002241:Carbohydrates / Q000032:analysis; D019281:Dimerization; D004492:Edetic Acid / Q000494:pharmacology; D020536:Enzyme Activators / Q000494:pharmacology; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007700:Kinetics; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000378:metabolism; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D012233:Rhizopus / Q000737:chemistry* / Q000201:enzymology*; D013696:Temperature; D014198:Trehalase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D014199:Trehalose / Q000378:metabolism
D002241:Carbohydrates; D020536:Enzyme Activators; D008670:Metals; D004492:Edetic Acid; D014199:Trehalose; D014198:Trehalase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase