Role of the Salt Bridge Between Arg176 and Glu126 in the Thermal Stability of the Bacillus amyloliquefaciens α-Amylase (BAA)
Yazarlar (4)
Roseata Zonouzi Islamic Azad University, Science And Research Branch, İran
Khosro Khajeh Tarbiat Modares University, İran
Prof. Dr. Majıd MONAJJEMI Islamic Azad University, Science And Research Branch, İran
Naser Ghaemi University Of Tehran, İran
| Makale Türü | Özgün Makale (ESCI dergilerinde yayınlanan tam makale) | ||
| Dergi Adı | Journal of Microbiology and Biotechnology | ||
| Dergi ISSN | 1017-7825 Wos Dergi Scopus Dergi | ||
| Makale Dili | İngilizce | Basım Tarihi | 01-2013 |
| Cilt / Sayı / Sayfa | 23 / 1 / 7–14 | DOI | 10.4014/jmb.1205.05062 |
| Makale Linki | http://www.scopus.com/inward/record.url?eid=2-s2.0-84873650976&partnerID=MN8TOARS | ||
| Özet |
| In the Bacillus amyloliquefaciens α-amylase (BAA), the loop (residues 176-185; region I) that is the part of the calcium-binding site (CaI, II) has two more amino acid residues than the α-amylase from Bacillus licheniformis (BLA). Arg176 in this region makes an ionic interaction with Glu126 from region II (residues 118-130), but this interaction is lost in BLA owing to substitution of R176Q and E126V. The goal of the present work was to quantitatively estimate the effect of ionic interaction on the overall stability of the enzyme. To clarify the functional and structural significance of the corresponding salt bridge, Glu126 was deleted (ΔE126) and converted to Val (E126V), Asp (E126D), and Lys (E126K) by site-directed mutagenesis. Kinetic constants, thermodynamic parameters, and structural changes were examined for the wild-type and mutated forms using UV-visible, atomic absoption, and fluorescence emission spectroscopy. Wild-type exhibited higher k |
| Anahtar Kelimeler |
| Bacillus amyloliquefaciens α-amylase | Ionic interaction | Site-directed mutagenesis | Thermal stability |
| Atıf Sayıları | |
| Web of Science | 13 |
| Scopus | 34 |