A novel non-thermostable deuterolysin from Aspergillus oryzae

• Published in: Bioscience, biotechnology, and biochemistry Vol. 80; no. 9; pp. 1813 - 1819
• Main Authors: Maeda, Hiroshi, Katase, Toru, Sakai, Daisuke, Takeuchi, Michio, Kusumoto, Ken-Ichi, Amano, Hitoshi, Ishida, Hiroki, Abe, Keietsu, Yamagata, Youhei
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01.09.2016
• Subjects: Aspergillus oryzae; Aspergillus oryzae - enzymology; Aspergillus oryzae - genetics; deuterolysin; Enzyme Stability - genetics; expression specificity; Fungal Proteins - biosynthesis; Fungal Proteins - chemistry; Fungal Proteins - genetics; Gene Expression Regulation, Fungal; Metalloendopeptidases - genetics; Nitrates - chemistry; Substrate Specificity; Temperature; thermostability; expression specificity; deuterolysin; Aspergillus oryzae; thermostability
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1080/09168451.2016.1166933

Three putative deuterolysin (EC 3.4.24.29) genes (deuA, deuB, and deuC) were found in the Aspergillus oryzae genome database ( http://www.bio.nite.go.jp/dogan/project/view/AO ). One of these genes, deuA, was corresponding to NpII gene, previously reported. DeuA and DeuB were overexpressed by recombinant A. oryzae and were purified. The degradation profiles against protein substrates of both enzymes were similar, but DeuB showed wider substrate specificity against peptidyl MCA-substrates compared with DeuA. Enzymatic profiles of DeuB except for thermostability also resembled those of DeuA. DeuB was inactivated by heat treatment above 80° C, different from thermostable DeuA. Transcription analysis in wild type A. oryzae showed only deuB was expressed in liquid culture, and the addition of the proteinous substrate upregulated the transcription. Furthermore, the NaNO 3 addition seems to eliminate the effect of proteinous substrate for the transcription of deuB. DeuB was a non-thermostable deuterolysin from A. oryzae. The transcription of the gene was promoted by protein substrates, but the promotion was eliminated by adding inorganic nitrogen source such as NaNO 3 .