A spore-lytic enzyme released from Bacillus cereus spores during germination.
The exudate of fully germinated spores of Bacillus cereus IFO 13597 in 0.25 M sodium phosphate buffer, pH 7.0, was found to contain a spore-lytic enzyme. This enzyme was found to cause loss of absorbance in coat-stripped spore suspensions and phase-darkening of the spores but had minimal activity on isolated peptidoglycan substrates. The enzyme was purified in an active form and identified as a 24 kDa protein which is either an amidase or a peptidase. The amino-terminal 19 residues had the following sequence: FSNQVIQRGASGEKVIELQ. The spore-lytic enzyme retained its activity in a medium of a relatively high ionic strength containing a non-ionic surfactant such as nonaethyleneglycol n-dodecyl ether. This activity was optimum at a salt concentration of about 30 mM in assay buffer at neutral pH. In contrast to the enzyme in a spore-bound form, the enzyme in solution was shown to be heat-sensitive and was readily inactivated by thiol reagents.
Makino
S
S
Department of Applied Biological Science, School of Agricultural Science, Nagoya University, Aichi, Japan.
Ito
N
N
Inoue
T
T
Miyata
S
S
Moriyama
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology* / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D006867:Hydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D007106:Immune Sera; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009994:Osmolar Concentration; D010457:Peptidoglycan / Q000187:drug effects; D017386:Sequence Homology, Amino Acid; D013171:Spores, Bacterial / Q000187:drug effects / Q000201:enzymology; D013501:Surface-Active Agents / Q000494:pharmacology; D013696:Temperature
D007106:Immune Sera; D010457:Peptidoglycan; D013501:Surface-Active Agents; D006867:Hydrolases