An on-demand metalloprotease from psychro-tolerant Exiguobacterium undae Su-1, the activity and stability of which are controlled by the Ca2+ concentration.
We reported an on-demand type of metalloprotease from Exiguobacterium undae Su-1. Although this species of bacterium is known to inhabit the permafrost, there are no reports on either strong proteases or peptidases. We found that Su-1 protease is superior to commercially available proteases in proteolytic activity in a lower to normal range of temperature (10-50 °C) as well as in rapid inactivation heat-dependently on the Ca2+ concentration. These characteristics meet well with the demands from food processing and manufacturing. Biochemical investigations of the purified enzyme and protein structural analysis after gene cloning confirmed that Su-1 protease conserved high identity in its primary sequence with thermophilic proteases of the M4 family. On the other hand, its flexibility was enhanced when one Ca2+ binding site was lost and by replacement for proline and isoleucine residues.
Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Japan.
Junko
J
Harada
Shusaku
S
Takaku
Kunihiko
K
Watanabe
D000595:Amino Acid Sequence; D001406:Bacillaceae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology*; D003001:Cloning, Molecular; D003080:Cold Temperature; D004795:Enzyme Stability; D004926:Escherichia coli; D005524:Food Technology; D006863:Hydrogen-Ion Concentration; D007532:Isoleucine / Q000737:chemistry / Q000235:genetics; D045726:Metalloproteases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011392:Proline / Q000737:chemistry / Q000235:genetics; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D007532:Isoleucine; D011392:Proline; D045726:Metalloproteases; D002118:Calcium