| Yazarlar |
Prof. Dr. Elif SEVİM
Ahi Evran Üniversitesi, Türkiye |
Kadriye İnan Bektaş
Karadeniz Teknik Üniversitesi, Türkiye |
Prof. Dr. Ali SEVİM
Ahi Evran Üniversitesi, Türkiye |
|
Sabriye Çanakçı
Karadeniz Teknik Üniversitesi, Türkiye |
|
İclal Şahin
|
|
Ali Osman Beldüz
Karadeniz Teknik Üniversitesi, Türkiye |
| Özet |
| In order to characterize two α-L-arabinofuranosidases (α-L-AFases), Abf1Geo12 and Abf2Geo12, produced by Geobacillus stearothermophilus strain 12, the genes (abf 1 and abf 2) coding for these enzymes were cloned and sequenced. Based on the protein sequence similarities, approximately 57 kDa two α-L-AFases were assigned to the glycoside hydrolase family 51. To obtain pure enzymes, the abf 1 and abf 2 genes were cloned into pET28a+ expression vector and recombinant α-L-AFases were produced in E.coli BL21(DE3): PLysS. Characterization of recombinant α-L-AFases revealed that Abf1Geo12 and Abf2Geo12 were active in a broad temperature range from 50 to 85°C and from 40 to 80°C, respectively. Also, the Abf1Geo12 was active in a broad pH range from 5.0 to 9.0. The optimum pH and temperature for Abf1Geo12 were determined as pH 6.0 and 65°C, respectively, whereas the optimum pH and temperature for Abf2Geo12 were determined as pH 5.5 and 60°C, respectively. Based on characterization studies, it was determined that the Abf1Geo12 was more stable than Abf2Geo12 and previously identified α-L-AFases from G. stearothermophilus. Using p-nitrophenyl α-L-arabinofuranoside as a substrate, the Km and Vmax values for Abf1Geo12 and Abf2Geo12 were determined as 0.31 mM and 290 U/mg for the former enzyme and 0.19 mM and 213.2 U/mg for the latter enzyme, respectively. The activities of Abf1Geo12 and Abf2Geo12 were strongly inhibited by 1 mM Hg2+. Interestingly, Cu2+ and Co2+ stimulated the activity of Abf1Geo12, but they reduced the activity of Abf2Geo12. The recombinant enzymes released L-arabinose from sugar beet arabinan, arabinobiose, arabinotriose, arabinotetraose and arabinopentaose. Consequently, these characterized two enzymes may be used in industrial fields since they are stable at high temperatures. |
| Anahtar Kelimeler |
| Geobacillus stearothermophilus | thermophilic bacteria | thermostable enzymes | α-L-Arabinofuranosidases |
| Makale Türü | Özgün Makale |
| Makale Alt Türü | SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale |
| Dergi Adı | Biologia |
| Dergi ISSN | 1336-9563 |
| Dergi Tarandığı Indeksler | SCI-Expanded |
| Makale Dili | İngilizce |
| Basım Tarihi | 01-2017 |
| Cilt No | 72 |
| Sayı | 8 |
| Sayfalar | 831 / 839 |
| Doi Numarası | 10.1515/biolog-2017-0099 |
| Makale Linki | http://www.degruyter.com/view/j/biolog.2017.72.issue-8/biolog-2017-0099/biolog-2017-0099.xml |
| Atıf Sayıları | |
| SCOPUS | 3 |
| Google Scholar | 2 |
