[Bacillus cereus chitinases: isolation and characteristics].
Three chitinases (M(r) = 68, 52 and 38 kDa) have been isolated from the cultural filtrate of Bacillus cereus strain VKPM B-6838 by stepwise hydrophobic chromatography on butyl-Toyopearl and gel filtration on Superdex 75 (FPLC). The chitinases are stable in the pH range 4-10 and have the same pH optimum of activity. The 68 and 38 kDa enzymes display the highest activity at 60 degrees C. while the 52 kDa chitinase-at 50 degrees C. In contrast with the 68- and 52 kDa enzymes, the 38 kDa chitinase hydrolyzes not only colloidal but also "crystalline" chitin and chitosan. None of the chitinases hydrolyzes chitobiose. The N-terminal sequences (10 amino acids) of the 52 and 38 kDa chitinases do not reveal structural similarity between themselves or to other known bacterial chitinases. The 68 kDa chitinase is not immunologically related to the 52 and 38 kDa enzymes. The results obtained suggest that the 68, 52 and 38 kDa chitinase are the unique proteins.
Trachuk
L A
LA
Shemiakina
T M
TM
Chestukhina
G G
GG
Stepanov
V M
VM
D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000201:enzymology*; D002688:Chitinases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity
D002688:Chitinases
Khitinazy Bacillus cereus: vydelenie i kharakteristika.