Related Experiment Video
Updated: Aug 18, 2026

A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Published on: November 7, 2012
Mutational effect for stability in a conserved region of thermolysin
Y Matsumiya1, K Nishikawa, K Inouye
1Department of Bioscience and Technology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Japan.
Aims:
To investigate the mutational effect for the stability of thermolysin (TLN) in conserved regions.
Methods And Results:
Mutational effects for stability at autodegradation sites of TLN in conserved region were studied. The bands of mutant TLN (34 kDa) on SDS-PAGE were decreased. However, those of mutant TLN cultivated with CaCl2 recovered to the same level as WT TLN. Dialysis study shows that these mutant TLN require more calcium ions than WT TLN.
Conclusions:
From these results, calcium affinity of mutant TLN in the conserved regions seem to become weak, subsequently mutant TLN were easily autodegraded in the case of low concentration of CaCl2.
Significance And Impact Of The Study:
The autodegradation sites located in conserved regions of bacilli neutral proteases are important for the tertiary structure formation concerning the stability of the protein.
Related Concept Videos
Protein Folding
Gene Evolution - Fast or Slow?
In contrast, regions which code...
Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
Bacterial Protein Maturation
Mutations in Microorganisms

