کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
11019565 | 1717633 | 2019 | 34 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Functional characterisation of cellobiohydrolase I (Cbh1) from Trichoderma virens UKM1 expressed in Aspergillus niger
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Cellobiohydrolases catalyze the processive hydrolysis of cellulose into cellobiose. Here, a Trichoderma virens cDNA predicted to encode for cellobiohydrolase (cbhI) was cloned and expressed heterologously in Aspergillus niger. The cbhI gene has an open reading frame of 1518 bp, encoding for a putative protein of 505 amino acid residues with a calculated molecular mass of approximately 54â¯kDa. The predicted CbhI amino acid sequence has a fungal type carbohydrate binding module separated from a catalytic domain by a threonine rich linker region and showed high sequence homology with glycoside hydrolase family 7 proteins. The partially purified enzyme has an optimum pH of 4.0 with stability ranging from pH 3.0 to 6.0 and an optimum temperature of 60â¯Â°C. The partially purified CbhI has a specific activity of 4.195 Umgâ1 and a low Km value of 1.88â¯mM when p-nitrophenyl-β-D-cellobioside (pNPC) is used as the substrate. The catalytic efficiency (kcat/Km) was 5.68â¯Ãâ¯10â4â¯mMâ1sâ1, which is comparable to the CbhI enzymes from Trichoderma viridae and Phanaerochaete chrysosporium. CbhI also showed activity towards complex substrates such as Avicel (0.011 Umgâ1), which could be useful in complex biomass degradation. Interestingly, CbhI also exhibited a relatively high inhibition constant (Ki) for cellobiose with a value of 8.65â¯mM, making this enzyme more resistant to end-product inhibition compared to other fungal cellobiohydrolases.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Protein Expression and Purification - Volume 154, February 2019, Pages 52-61
Journal: Protein Expression and Purification - Volume 154, February 2019, Pages 52-61
نویسندگان
Anis Farhan Fatimi Ab Wahab, Noor Adila Abdul Karim, Jonathan Guyang Ling, Nurain Shahera Hasan, Hui Yee Yong, Izwan Bharudin, Shazilah Kamaruddin, Farah Diba Abu Bakar, Abdul Munir Abdul Murad,