The esterolytic activity of epidermolytic toxins.
The two epidermolytic toxins were shown to have intrinsic N-t-butyloxycarbonyl-L-glutamic acid alpha-phenyl esterase activity. The activity was dependent on free toxin pKa values of 6.6 and 6.8 for ETA and ETB respectively. ETB incorporated 0.97 mol of radiolabelled di-isopropyl phosphorofluoridate/mol of protein with loss of esterolytic and epidermolytic activities. The correspondence of epidermolytic and esterolytic activities in ETA and ETB during thermal inactivation and reaction with di-isopropyl phosphorofluoridate, together with the inactivity of the mutant protein ETA S195G, demonstrates that the two activities are dependent on a single active serine residue in each protein.
Bailey
C J
CJ
Department of Biochemistry, Trinity College, Dublin, Ireland.
Redpath
M B
MB
D000818:Animals; D004795:Enzyme Stability; D004950:Esterases / Q000378:metabolism*; D005083:Exfoliatins / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism; D006358:Hot Temperature; D006868:Hydrolysis; D007531:Isoflurophate / Q000378:metabolism; D007700:Kinetics; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D012694:Serine / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism
D005083:Exfoliatins; D005971:Glutamates; D007531:Isoflurophate; D012694:Serine; C074946:N-t-butyloxycarbonyl-glutamic acid alpha phenyl ester; D004950:Esterases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus