Linked Life Data

10026271

Source:http://linkedlifedata.com/resource/pubmed/id/10026271

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1999-3-4
pubmed:abstractText
The enzyme UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc deacetylase (LpxC) catalyzes the committed step in the biosynthesis of lipid A and is therefore a potential antibiotic target. Inhibition of this enzyme by hydroxamate compounds [Onishi, H. R.; Pelak, B. A.; Gerckens, L. S.; Silver, L. L.; Kahan, F. M.; Chen, M. H.; Patchett, A. A.; Stachula, S. S.; Anderson, M. S.; Raetz, C. R. H. (1996) Science 274, 980-982] suggested the presence of a metal ion cofactor. We have investigated the substrate specificity and metal dependence of the deacetylase using spectroscopic and kinetic analyses. Comparison of the steady-state kinetic parameters for the physiological substrate UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc and an alternative substrate, UDP-GlcNAc, demonstrates that the ester-linked R-3-hydroxymyristoyl chain increases kcat/KM (5 x 10(6))-fold. Metal-chelating reagents, such as dipicolinic acid (DPA) and ethylenediaminetetraacetic acid, completely inhibit LpxC activity, implicating an essential metal ion. Plasma emission spectroscopy and colorimetric assays directly demonstrate that purified LpxC contains bound Zn2+. This Zn2+ can be removed by incubation with DPA, causing a decrease in the LpxC activity that can be restored by subsequent addition of Zn2+. However, high concentrations of Zn2+ also inhibit LpxC. Addition of Co2+, Ni2+, or Mn2+ to apo-LpxC also activates the enzyme to varying degrees while no additional activity is observed upon the addition of Cd2+, Ca2+, Mg2+, or Cu2+. This is consistent with the profile of metals that substitute for catalytic zinc ions in metalloproteinases. Co2+ ions stimulate LpxC activity maximally at a stoichiometry of 1:1. These data demonstrate that E. coli LpxC is a metalloenzyme that requires bound Zn2+ for optimal activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Amidohydrolases, http://linkedlifedata.com/resource/pubmed/chemical/Cations, Divalent, http://linkedlifedata.com/resource/pubmed/chemical/Chelating Agents, http://linkedlifedata.com/resource/pubmed/chemical/Edetic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Metalloproteins, http://linkedlifedata.com/resource/pubmed/chemical/Metals, http://linkedlifedata.com/resource/pubmed/chemical/Picolinic Acids, http://linkedlifedata.com/resource/pubmed/chemical/Serum Albumin, Bovine, http://linkedlifedata.com/resource/pubmed/chemical/UDP-3-O-acyl-N-acetylglucosamine..., http://linkedlifedata.com/resource/pubmed/chemical/Zinc, http://linkedlifedata.com/resource/pubmed/chemical/dipicolinic acid
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1902-11
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase of Escherichia coli is a zinc metalloenzyme.
pubmed:affiliation
Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.