Proteolysis of Mesophilic and Thermophilic a-Amylases

Comparative studies on trifluoroethanol (TFE) state of a thermophilic α-amylase and its mesophilic counterpart: limited proteolysis, conformational analysis, aggregation and reactivation of the enzymes

“…A correlation between sites of proteolysis and segmental mobility in thermostable proteins has also been previously established [30,31]. Our comparative studies indicate that the BLA has shown a greater resistance to digestion by the trypsin, thermolysin, and proteinase K [31,and Khajeh,unpublished data].…”

“…Previous studies have shown that the specific or preferential fission of peptide bond(s) by limited proteolysis [30,31] is a useful way to probe structural properties of globular proteins [32,33]. Limited proteolysis has been performed in the presence of different amounts of TFE by incubating BLA and BAA with the thermolysin under various experimental conditions of enzyme to substrate ratio, temperature and duration of incubation.…”

Cloning, Expression, and Purification of Xylanase Gene from Bacillus licheniformis for Use in Saccharification of Plant Biomass

“…The temperature stability of our purified recombinant xylanase was rationally higher than that of other xylanases purified from Bacillus sp., Bacillus mojavensis, Bacillus subtilis, and B. pumilus [33,[38][39][40]. At higher temperature, the structural features of the thermostable enzymes may change and become flexible [41]. This feature of the xylanases makes them attractive for industrial applications and for saccharification of biomass.…”

Stabilization of Bacillus licheniformis α-amylase by specific antibody which recognizes the N-terminal fragment of the enzyme

“…Trypsin cleaves peptide bonds, C-terminal to basic amino acids, lysine and arginine. Previously, we showed that digestion of BLA with trypsin results in two fragments 18 kDa (TF18K) and 38 kDa (TF38K) [10,11]. In the present study, we isolated both fragments by preparative gel electrophoresis and reverse phase (RP)-HPLC.…”

“…In addition, the activity of this enzyme increased about 15% upon tryptolytic digestion [10]. Thus it was proposed that BLA conserves its conformation upon limited proteolysis [10,11]. Here, in order to isolate the cleaved fragments, aliquots (30 mg protein) of proteolytic mixture were applied to several kinds of chromatography methods.…”