Mutational effect for stability in a conserved region of thermolysin.
OBJECTIVE
To investigate the mutational effect for the stability of thermolysin (TLN) in conserved regions.


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.


CONCLUSIONS
The autodegradation sites located in conserved regions of bacilli neutral proteases are important for the tertiary structure formation concerning the stability of the protein.
Matsumiya
Y
Y
Department of Bioscience and Technology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Japan.
Nishikawa
K
K
Inouye
K
K
Kubo
M
M
D000595:Amino Acid Sequence; D001407:Bacillus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D002122:Calcium Chloride; D003001:Cloning, Molecular; D003470:Culture Media; D007218:Industrial Microbiology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D016415:Sequence Alignment; D013820:Thermolysin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D003470:Culture Media; D013820:Thermolysin; D002122:Calcium Chloride