Article (Scientific journals)
Substrate-activated zinc binding of metallo-beta-lactamases - Physiological importance of the mononuclear enzymes
Wommer, S.; Rival, S.; Heinz, U. et al.
2002In Journal of Biological Chemistry, 277 (27), p. 24142-24147
Peer Reviewed verified by ORBi
 

Files


Full Text
Wommer_2002.pdf
Publisher postprint (643.07 kB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Abstract :
[en] We have investigated the influence of substrate binding on the zinc ion affinity of representatives from the three metallo-g-lactamase subclasses, B1 (BcII from Bacillus cereus and BlaB from Chryseobacterium meningosepticum), B2 (CphA from Aeromonas hydrophila), and B3 (L1 from Stenotrophomonas maltophilia). By competition experiments with metal-free apoenzymes and chromophoric zinc chelators or EDTA, we determined the dissociation constants in the absence and presence of substrates. For the formation of the monozine enzymes we determined constants of 1.8, 5.1, 0.007, and 2.6 nm in the absence and 13.6, 1.8, 1.2, and 5.7 pm in the presence of substrates for Bell, BlaB, CphA, and L1, respectively. A second zinc ion binds in the absence (presence) of substrates with considerably higher dissociation constants, namely 1.8 (0.8), 0.007 (0.025), 50 (1.9), and 0.006 (0.12) mum for BcII, BlaB, CphA, and L1, respectively. We have concluded that the apo form might be the prevailing state of most of the metallo-beta-lactamases under physiological conditions in the absence of substrates. Substrate availability induces a spontaneous self-activation due to a drastic decrease of the dissociation constants, resulting in the formation of active mononuclear enzymes already at picomolar free zinc ion concentrations. In the presence of substrates, the binuclear state of the enzymes only exists at unphysiologic high zinc concentrations and might be of no biological relevance. From the competition experiments with EDTA it is further concluded that the reactivation rate does not depend on the pool of free zinc ions but proceeds via the EDTA-Zn(II)-enzyme ternary complexes.
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Wommer, S.
Rival, S.
Heinz, U.
Galleni, Moreno ;  Université de Liège - ULiège > Département des sciences de la vie > Macromolécules biologiques
Frère, Jean-Marie ;  Université de Liège - ULiège > Département des sciences de la vie > Département des sciences de la vie
Franceschini, N.
Amicosante, G.
Rasmussen, B.
Bauer, R.
Adolph, H. W.
Language :
English
Title :
Substrate-activated zinc binding of metallo-beta-lactamases - Physiological importance of the mononuclear enzymes
Publication date :
05 July 2002
Journal title :
Journal of Biological Chemistry
ISSN :
0021-9258
eISSN :
1083-351X
Publisher :
Amer Soc Biochemistry Molecular Biology Inc, Bethesda, United States - Maryland
Volume :
277
Issue :
27
Pages :
24142-24147
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 24 November 2015

Statistics


Number of views
169 (0 by ULiège)
Number of downloads
0 (0 by ULiège)

Scopus citations®
 
108
Scopus citations®
without self-citations
93
OpenCitations
 
106

Bibliography


Similar publications



Contact ORBi