JBC, Vol. 250, Issue 18, 7231-7238, Sep, 1975
Interaction of N-acetylmuramic acid L-alanine amidase with cell wall polymers
D. R. Herbold and L. Glaser
In a previous communication (J. Biol. Chem. (1975) 250, 1676-1682), methods
were described for the purification of the N-acetylmuramic acid L-alanine
amidase from Bacillus subtilis ATCC 6051 and of a modifier protein which
combines stoichiometrically with the enzyme and stimulates the activity
approximately 3-fold. A detailed examination of the wall cleavage products
obtained in the absence and in the presence of modifier indicates that the
major effect of the modifier is not to change the enzyme velocity, but
rather to change the pattern of cleavage from a more random pattern, when
enzyme alone hydrolyzes the cell wall, to a sequential pattern in the
presence of modifier protein. Tight binding of the enzyme to the cell wall
and functional interaction with the modifier occur only when cell walls
from Bacillus subtilis ATCC 6051 containing or teichoic acid are used as a
substrate. We suggest that a general function of cell wall teichoic acids
is to act as specific "allosteric" ligands for bacterial cell wall lytic
enzymes as has been demonstrated previously in Pneumococci (Tomasz, A., and
Westphal, M (1971) Proc. Natl. Acad. Sci. U.S.A. 68, 2627-2630).