Studies on the inhibition of neutral proteases by 1,10-phenanthroline

Feder, Joseph; Garrett, L.R.; Kochavi, Daniel.

doi:10.1016/0005-2744(71)90216-6

Cited by 21 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conclusions about the mechanism of inhibition by chelating agents of collagenases from rabbit cornea (Berman & Manabe, 1973), human skin, rat skin and rat uterus (Seltzer et al, 1977) were that EDTA treatment produced apocollagenase but that 1,10phenanthroline inhibited by binding to the enzyme. Our findings on the effect of 1, 10-phenanthroline on rabbit bone collagenase, however, resemble those obtained by Feder et al (1971) on thermolysin. The preparation of a collagenase incorporating 6SZn2+ has been achieved previously by growing rabbit corneal cultures in the presence of 6SZn2+ (Berman & Manabe, 1973).…”

Section: Discussionsupporting

confidence: 81%

Zinc metalloenzyme properties of active and latent collagenase from rabbit bone

Swann¹,

Reynolds²,

Galloway³

1981

Biochemical Journal

View full text Add to dashboard Cite

1. Inhibition of collagenase from rabbit bone cultures by the chelating agents 1,10-phenanthroline and EDTA is almost completely reversed by Zn2+; other metal cations are less effective in reversing the inhibition. Optimal restoration of activity is achieved at Zn2+ concentrations below that of the chelator, but excess of Zn2+ is inhibitory. 2. Prolonged incubation of collagenase with either chelator causes irreversible inactivation. This inactivation is prevented by Zn2+ at the same concentrations needed to reverse the primary inhibition. 3. Collagenase incorporates 65Zn by exchange when incubated with 1,10-phenanthroline and Zn2+ containing this radioactive isotope. The 65Zn2+ can be removed from its binding site in collagenase by 1,10-phenanthroline or EDTA. Irreversible inactivation of collagenase by chelators destroys its ability to incorporate 65Zn2+. 4. Latent collagenase, the inhibited form in which collagenase first appears in culture, behaves similarly to the active enzyme in 65Zn2+-exchange experiments, but is resistant to irreversible inactivation by chelators. 5. It is concluded that collagenase is a zinc metalloenzyme that forms an inactive and unstable apoenzyme on treatment with chelators. The bound inhibitor component of latent collagenase evidently stabilizes the apoenzyme.

show abstract

Section: Discussionsupporting

confidence: 81%

Zinc metalloenzyme properties of active and latent collagenase from rabbit bone

Swann¹,

Reynolds²,

Galloway³

1981

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…This binding apparently occurs without dissociation of the complex since it is observed in the crystal and, for the wildtype enzyme, does not disrupt the crystal. The Zn(II) at the intermolecular site is not accessible to the solvent (10), which may be one reason that its affinity for binding is 10 6 -fold less than that for binding of Zn(II) at the structurally identical site in thermolysin which is solvent accessible (37). Ad-…”

Section: Discussionmentioning

confidence: 99%

Cation-Promoted Association of Escherichia coli Phosphocarrier Protein IIA^Glc with Regulatory Target Protein Glycerol Kinase: Substitutions of a Zinc(II) Ligand and Implications for Inducer Exclusion

Roseman

et al. 1998

Biochemistry

View full text Add to dashboard Cite

In Escherichia coli, inducer exclusion is one mechanism by which glucose prevents unnecessary expression of genes needed for metabolism of other sugars. The basis for this mechanism is binding of the unphosphorylated form of the glucose-specific phosphocarrier protein of the phosphoenolpyruvate:glycose phosphotransferase system, IIAGlc (also known as IIIGlc), to a variety of target proteins to prevent uptake or synthesis of the inducer. One of these target proteins is glycerol kinase (EC 2.1.7.30, ATP:glycerol 3-phosphotransferase), which is inhibited by IIAGlc. Glycerol kinase is the only IIAGlc target protein for which the structure of the complex is known. Association of these two proteins forms an intermolecular binding site for Zn(II) with metal ligands contributed by each protein, and Zn(II) enhances IIAGlc inhibition [Feese, M., Pettigrew, D. W., Meadow, N. D., Roseman, S., and Remington, S. J. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 3544-3548]. Here, we show that the Zn(II) enhancement can be described quantitatively by a model with binding of Zn(II) to the complex with an apparent dissociation constant of less than 1 microM at pH 7.0 and 25 degreesC. Initial velocity studies show that IIAGlc is an uncompetitive inhibitor with respect to both substrates, and the mechanism of inhibition is not altered by Zn(II). The Zn(II)-liganding residue contributed by glycerol kinase (Glu478) is substituted by using site-directed mutagenesis to construct the enzymes E478C, E478D, E478H, and E478Q. The substitutions have only small effects on the inhibition by IIAGlc in the absence of Zn(II), the catalytic properties, or other allosteric regulation. However, all of the substitutions abolish the Zn(II) enhancement of IIAGlc inhibition, and the X-ray crystallographic structures of the complexes of IIAGlc with the E478C and E478H mutants show these substitutions abolish binding of Zn(II) to the intermolecular site. These results support the hypothesis that Zn(II) enhances the affinity for complex formation by binding at the intermolecular site, i.e., cation promoted association. The high affinity for Zn(II) binding to the complex and the ability of the other four amino acid residues to efficiently substitute for Glu478 in all functions except binding of Zn(II) suggest that cation promoted association of these two proteins may have a role in inducer exclusion in vivo.

show abstract

“…The zinc affinity of ZntR is significantly higher than that reported for other native zinc proteins and most peptides characterized to date (Table ) . ZntR protein can successfully compete thermodynamically with endogenous zinc-binding apo-proteins as well as other metal-binding apo-proteins for the free zinc ions within the E. coli cell.…”

mentioning

confidence: 86%