Extracellular proteolytic processing ofAspergillus awamori GAI into GAII is supported by physico-chemical evidence
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The proportion of glucoamylases, GAI and GAII, in the culture supernatant ofAspergillus awamori fermentations depends on the medium C/N ratio in such a way that the transformation of GAI into GAII is favored by the existence of a surplus of the carbon source in the growth medium. This condition also favors the appearance of the proteolytic activity. The authors report the observation that the shift in the isoenzyme proportion was concomitant to the peak of proteolytic activity. A peptide that may have resulted from the continuous degradation of the GAI C-terminal peptide, Gp-1, was isolated by gel filtration and purified by reversephase chromatography. This peptide matched with the region G14-A34 of the substrate-binding domain of GAI, thus reinforcing the hypothesis of the extracellular proteolytic processing of GAI.
Index EntriesAspergillus awamori glucoamylase GAI and GAII glu-coamylase isoenzymes processing isoenzymes extracellular processing isoenzymes proteolytic processing
- 3.Hayashida, S., Nakahara, K., Kuroda, K., Kamachi, T., Otha, K., Iwanaga, S., Miyata, T. and Sakaki, Y. (1988),Agric. Biol. Chem. 52(1), 273–275.Google Scholar
- 4.Hayashida, S., (1975),Agric. Biol. Chem. 39(11), 2093–2099.Google Scholar
- 5.Bartoszewitz, K., (1986),Ada Biochim. Polonica 23, 17–29.Google Scholar
- 8.Charney, J. and Tomarelli, R. M. (1947),J. Biol. Chem. 171, 501–505.Google Scholar