Volume 272, Number 40,
Issue of October 3, 1997
pp. 24755-24758
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.
COMMUNICATION:
Inhibition of Aminoglycoside Antibiotic Resistance Enzymes by
Protein Kinase Inhibitors
(Received for publication, July 16, 1997, and in revised form, August 14, 1997)
Denis M.
Daigle
,
Geoffrey A.
McKay
and
Gerard D.
Wright
From the Department of Biochemistry, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
Bacterial resistance to the aminoglycoside
antibiotics is manifested primarily through the expression of enzymes
which covalently modify these drugs. One important mechanism of
aminoglycoside modification is through ATP-dependent
O-phosphorylation, catalyzed by a family of aminoglycoside
kinases. The structure of one of these kinases, APH(3
)-IIIa has
recently been determined by x-ray crystallography, and the general fold
is strikingly similar to eukaryotic protein kinases (Hon, W. C.,
McKay, G. A., Thompson, P. R., Sweet, R. M., Yang,
D. S. C., Wright, G. D., and Berghuis, A. M. (1997)
Cell 89, 887-895). Based on this similarity, we have examined the effect of known inhibitors of eukaryotic protein kinases
on two aminoglycoside kinases, APH(3
)-IIIa and the enzyme AAC(6
)-APH(2") which also exhibits acetyl-CoA-dependent
aminoglycoside modification activity. We report that several known
protein kinase inhibitors are also good inhibitors of aminoglycoside
kinases. Compounds belonging to the isoquinolinesulfonamide group are
especially effective in this regard, giving competitive inhibition in
the micromolar range with respect to ATP and noncompetitive inhibition versus the aminoglycoside substrate. This study
provides the basis for future aminoglycoside kinase inhibitor design
and for the development of compounds which could reverse antibiotic
resistance in the clinic.