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Characterisation of acid proteases from a fusant F 76 and its progenitors A spergillus oryzae HN 3042 and A spergillus niger CICC 2377
Author(s) -
Xu Defeng,
Li Caihong,
Wang Yaling,
Sun Lijun,
Zhao Haifeng,
Zhao Mouming
Publication year - 2013
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2012.03142.x
Subject(s) - proteases , protease , chemistry , enzyme , nuclear chemistry , biochemistry
Summary The characteristics of a novel acid protease from a fusant F 76 were comparatively evaluated with those from its progenitors A spergillus oryzae HN 3042 and A . niger CICC 2377. The UV spectra of these three acid proteases were similar, but fluorescence spectra were different. The acid protease from F 76 contained 7.1% α‐helix, 39.4% β‐sheet, 24.7% β‐turn and 32% aperiodic coil, unlike those from its progenitors. The acid protease from F76 was active in the temperature range of 35–55 °C with the optimum temperature of 40 °C and was stable in the p H range of 2.5–6.5 with the optimum p H of 3.5, while those values from A . oryzae HN 3042 and A . niger CICC 2377 were 45 °C, 4.0 and 40 °C, 3.5, respectively. The kinetic parameters of the acid protease from F 76 were different from its progenitors and the M ichaelis constant, maximum velocity, activation energy, and attenuation index were 0.96 mg mL −1 , 135.14 μmol min −1 mg −1 , 64.11 kJ mol −1 and 0.59, respectively.