Comparative study on proteinase R, T, and K from Tritirachiam album limber.
Proteinase R and T purified from Tritirachiam album limber were characterized in comparison with proteinase K using circular dichroism (CD), enzyme activity, thermal melting, and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). CD analysis suggested that these three proteins possess some beta-sheet structure, with little alpha-helix except for proteinase R which showed about 14% alpha-helix. SDS-PAGE and gel filtration in 0.1% SDS indicated that proteinase T and K are resistant to SDS-induced unfolding similar to subtilisin. Thermal denaturation experiments showed the melting temperature for proteinase T to be 67 degrees and that for proteinase K to be 65 degrees in the absence of Ca2+, with higher melting temperatures in the presence of Ca2+. However, the enzyme activities of proteinase T and R were significantly lower than those of proteinase K.
Kolvenbach
C G
CG
Amgen Inc., Amgen Center, Thousand Oaks, CA.
Narhi
L O
LO
Lazenby
K
K
Samal
B
B
Arakawa
T
T
D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D019286:Endopeptidase K; D007700:Kinetics; D003904:Mitosporic Fungi / Q000201:enzymology*; D011487:Protein Conformation; D011489:Protein Denaturation; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D013381:Subtilisins / Q000302:isolation & purification / Q000378:metabolism*; D013816:Thermodynamics
D012697:Serine Endopeptidases; D013381:Subtilisins; C068011:proteinase R; C063415:proteinase T; D019286:Endopeptidase K