Partial Separation and Characterization of Papaya Endo‐ and Exo‐Polygalacturonase
1982; Wiley; Volume: 47; Issue: 5 Linguagem: Inglês
10.1111/j.1365-2621.1982.tb04965.x
ISSN1750-3841
Autores Tópico(s)Polysaccharides and Plant Cell Walls
ResumoABSTRACT Exo‐ and endo‐polygalacturonases (EC 3.2.1.40 and EC 3.2.1.15) in papayas were extracted, purified 20‐ and 90‐fold, respectively, and characterized. Both enzymes functioned optimally at pH 4.6 and 45°C. Heat inactivation of the papaya PGases was biphasic and both phases followed first order kinetics. Decreasing the pH from 4.6 to 3.6 decreased the time required for their heat inactivation. The activation energies for the thermal inactivation at pH 3.6 and 4.6 were 85 and 92 kcal/mol, respectively, for endo‐PGase (PG I) and 140 and 102 kcal/mol, respectively, for exo‐PGase (PG II). The apparent molecular weight was determined by gel filtration to be 164,000 daltons for PG I and 34,000 daltons for PG II.
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