The anti-angiogenic agent fumagillin covalently modifies a conserved active-site histidine in the Escherichia coli methionine aminopeptidase.
Methionine aminopeptidase (MetAP) exists in two forms (type I and type II), both of which remove the N-terminal methionine from proteins. It previously has been shown that the type II enzyme is the molecular target of fumagillin and ovalicin, two epoxide-containing natural products that inhibit angiogenesis and suppress tumor growth. By using mass spectrometry, N-terminal sequence analysis, and electronic absorption spectroscopy we show that fumagillin and ovalicin covalently modify a conserved histidine residue in the active site of the MetAP from Escherichia coli, a type I enzyme. Because all of the key active site residues are conserved, it is likely that a similar modification occurs in the type II enzymes. This modification, by occluding the active site, may prevent the action of MetAP on proteins or peptides involved in angiogenesis. In addition, the results suggest that these compounds may be effective pharmacological agents against pathogenic and resistant forms of E. coli and other microorganisms.
Lowther
W T
WT
Institute of Molecular Biology, Howard Hughes Medical Institute and Department of Physics, University of Oregon, Eugene, OR 97403, USA.
McMillen
D A
DA
Orville
A M
AM
Matthews
B W
BW
D000626:Aminopeptidases / Q000737:chemistry* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D003510:Cyclohexanes; D017931:DNA Primers; D004926:Escherichia coli / Q000201:enzymology*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry* / Q000494:pharmacology; D006639:Histidine / Q000737:chemistry*; D013058:Mass Spectrometry; D063208:Methionyl Aminopeptidases; D009389:Neovascularization, Pathologic / Q000517:prevention & control*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012717:Sesquiterpenes
D003510:Cyclohexanes; D017931:DNA Primers; D005231:Fatty Acids, Unsaturated; D011994:Recombinant Proteins; D012717:Sesquiterpenes; D006639:Histidine; C026211:fumagillin; D000626:Aminopeptidases; D063208:Methionyl Aminopeptidases