Intramolecular nucleophilic attack of carboxyl on amides. The metal ion inhibited hydrolysis of N-(2-pyridyl)phthalamic acid and N-(2-phenanthrolyl)phthalamic acid

1977 ◽  
Vol 99 (11) ◽  
pp. 3762-3769 ◽  
Author(s):  
Thomas H. Fife ◽  
Vanessa Lum Squillacote
Keyword(s):  
Metal Ion ◽  
Nucleophilic Attack ◽  
Phthalamic Acid ◽  
Hydrolysis Of

scholarly journals The Mechanisms of Catalysis by Metallo -Lactamases

2008 ◽  
Vol 2008 ◽  
pp. 1-14 ◽  
Author(s):  
Michael I. Page ◽  
Adriana Badarau
Keyword(s):  
Water Molecule ◽  
Metal Ion ◽  
Hydrolytic Enzymes ◽  
Bound Water ◽  
Intrinsic Property ◽  
Carbonyl Oxygen ◽  
Nucleophilic Attack ◽  
Metal Ion Binding ◽  
Lactam Carbonyl ◽  
Hydrolysis Of

Class B -lactamases or metallo--lactamases (MBLs) require zinc ions to catalyse the hydrolysis of -lactam antibiotics such as penicillins, cephalosporins, carbapenems, and cephamycins. There are no clinically useful inhibitors against MBLs which are responsible for the resistance of some bacteria to antibiotics. There are two metal-ion binding sites that have different zinc ligands but the exact roles of the metal-ion remain controversial, and distinguishing between their relative importance is complex. The metal-ion can act as a Lewis acid by co-ordination to the -lactam carbonyl oxygen to facilitate nucleophilic attack and stabilise the negative charge developed on this oxygen in the tetrahedral intermediate anion. The metal-ion also lowers the pKa of the directly co-ordinated water molecule so that the metal-bound hydroxide ion is a better nucleophile than water and is used to attack the -lactam carbonyl carbon. An intrinsic property of binuclear metallo hydrolytic enzymes that depend on a metal-bound water both as the attacking nucleophile and as a ligand for the second metal-ion is that this water molecule, which is consumed during hydrolysis of the substrate, has to be replaced to maintain the catalytic cycle. With MBL this is reflected in some unusual kinetic profiles.

ChemInform Abstract: KINETICS OF THE METAL ION CATALYZED ESTER HYDROLYSIS OF O-ACETYL DI-2-PYRIDYL KETOXIME

1985 ◽  
Vol 16 (51) ◽  
Author(s):  
J. SUH ◽  
M. P. SUH ◽  
J. D. LEE
Keyword(s):  
Metal Ion ◽  
Ester Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

Metal Ion Catalysis in the Hydrolysis of Potassium Ethyl Oxalate

Nature ◽  
1964 ◽  
Vol 204 (4964) ◽  
pp. 1189-1190
Author(s):  
ROBERT W. HAY ◽  
NEIL J. WALKER
Keyword(s):  
Metal Ion ◽  
Metal Ion Catalysis ◽  
Hydrolysis Of

Metal ion effects on the acid hydrolysis of pyrophosphate

1964 ◽  
Vol 26 (8) ◽  
pp. 1415-1420 ◽  
Author(s):  
J.M. Rainey ◽  
M.M. Jones ◽  
W.L. Lockhart
Keyword(s):  
Acid Hydrolysis ◽  
Metal Ion ◽  
Ion Effects ◽  
Metal Ion Effects ◽  
Hydrolysis Of

scholarly journals Effect of metal ion on the stereoselective hydrolysis of optically active esters by modified polymers with covalently-linked dipeptide.

1987 ◽  
pp. 405-407
Author(s):  
Mamoru NANGO ◽  
Yoshiharu KIMURA ◽  
Yasuji IHARA ◽  
Nobuhiko KUROKI
Keyword(s):  
Metal Ion ◽  
Optically Active ◽  
Active Esters ◽  
Modified Polymers ◽  
Covalently Linked ◽  
Stereoselective Hydrolysis ◽  
Hydrolysis Of

Metal-ion facilitated hydrolysis of hippuryl-DL-β-phenyllactate, a carboxypeptidase substrate

1983 ◽  
Vol 78 ◽  
pp. 69-73 ◽  
Author(s):  
Rodney F. Boyer ◽  
Barbara C. Smith
Keyword(s):  
Metal Ion ◽  
Hydrolysis Of
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