scholarly journals Identification of cysteine as the reactive group in pyruvate kinase alkylated by 5-chloro-4-oxopentanoic acid

1976 ◽  
Vol 159 (2) ◽  
pp. 213-219 ◽  
Author(s):  
R A Chalkley ◽  
D P Bloxham
Keyword(s):  
Pyruvate Kinase ◽  
Peptide Mapping ◽  
Periodate Oxidation ◽  
Performic Acid ◽  
Acid Oxidation ◽  
Rabbit Muscle ◽  
Pentanoic Acid ◽  
Reactive Group ◽  
Muscle Pyruvate Kinase ◽  
Nabh4 Reduction

4-Hydroxypentanoic acid alanine thioether was synthesized and characterized by n.m.r. spectroscopy. This derivative corresponded to the modified amino acid obtained by allowing 5-chloro-4-oxo[3,5-3H]pentanoic acid to react with rabbit muscle pyruvate kinase. Performic acid oxidation of 4-oxo[3,5-3H]pentanoic acid alanine thioether in pyruvate kinase gave [3H]succinate (67%) and [3H]carboxymethylcysteine (33%) as expected. Evidence is presented to show that NaBH4 reduction followed by periodate oxidation and analysis of radioactive formaldehyde production may provide a convenient method for distinguishing between thiol and amino alkylation by halogenomethyl ketone compounds. Peptide ‘mapping’ confirms that the modification by 5-chloro-4-oxopentanoic acid occurs primarily at one region of pyruvate kinase.

scholarly journals Selective modification of rabbit muscle pyruvate kinase by 5-chloro-4-oxopentanoic acid

1976 ◽  
Vol 159 (2) ◽  
pp. 201-211 ◽  
Author(s):  
D P Bloxham ◽  
R A Chalkley
Keyword(s):  
Pyruvate Kinase ◽  
Active Site ◽  
Functional Group ◽  
Time Dependent ◽  
Rabbit Muscle ◽  
Pentanoic Acid ◽  
Basic Group ◽  
Muscle Pyruvate Kinase ◽  
Kinetics Of ◽  
Kinetics Of Inhibition

Rabbit muscle pyruvate kinase was irreverisbly inactivated by 5-chloro-4-oxopentanoic acid with a pKa of 9.2. The inhibition was time-dependent and was related to the 5-chloro-4-oxopentanoic acid concentration. Analysis of the kinetics of inhibition showed that the binding of the inhibitor showed positive co-operativity (n = 1.5 ± 0.2). Inhibition of pyruvate kinase by 5-chloro-4-oxopentanoic acid was prevented by ligands which bind to the active site. Their effectiveness was placed in the order Mg2+ > phosphoenolpyruvate > ATP ≫ ADP > pyruvate. Inhibitor-modified pyruvate kinase was unable to catalyse the detritiation of [3-3H]pyruvate in the ATP-promoted reaction, but it did retain 5-10% of the activity with either phosphate or arsenate as promoters. 5-Chlor-4-oxo-[3,5-3H]pentanoic acid was covalently bound to pyruvate kinase and demonstrated a stoicheiometry of 1 mol of inhibitor bound per mol of pyruvate kinase protomer. The incorporation of the inhibitor and the loss of enzyme was proportional. These results are discussed in terms of 5-chloro-4-oxopentanoic acid alkylating a functional group in the phosphoryl overlap region of the active site, and a model is presented in which this compound alkylates an active-site thiol in a reaction that is controlled by a more basic group at the active site.

Interaction of D-phenylalanine with Co(II)-substituted rabbit muscle pyruvate kinase: kinetic and optical properties

1982 ◽  
Vol 60 (9) ◽  
pp. 861-866
Author(s):  
Chiu-Yin Kwan ◽  
Robert C. Davis
Keyword(s):  
Amino Acids ◽  
Optical Properties ◽  
Pyruvate Kinase ◽  
Conformational Changes ◽  
Metal Ion ◽  
Inhibitory Effect ◽  
Rabbit Muscle ◽  
Divalent Metal Ion ◽  
Muscle Pyruvate Kinase ◽  
Difference Absorption

The kinetic and optical properties of Co(II)-substituted pyruvate kinase in the presence of D-phenylalanine (D-Phe) were investigated. The results are discussed in comparison with the effects of its optical isomer L-phenylalanine (L-Phe) on the same enzyme. The catalytic effect of D-Phe on rabbit muscle pyruvate kinase depended upon the nature of the activating divalent metal ion used. It has stimulatory effect on Mg(II)-activated enzyme, but inhibitory effect on Co(II)-activated enzyme. Unlike the inhibitory effect of L-Phe, the inhibition of Co(II)–enzyme by D-Phe was not sensitive to the changes of pH and temperature, could not be reversed by L-alanine (L-Ala), displayed hyperbolic kinetics, and was noncompetitive with respect to phosphoenolpyruvate saturation. D-Phe induced substantial visible circular dichroism (CD) spectral changes of Co(II)–enzyme similar to those induced by L-Phe. Although ultraviolet CD spectrum was not affected, D-Phe induced an ultraviolet difference absorption spectral change very similar to, but much smaller than, that induced by L-Phe. Our results support that D-Phe and other amino acids interact with the enzyme at two different sites: a common site, causing similar conformational changes which bear little direct kinetic relevance, and a kinetically relevant site, which is sterically dependent upon the side chain of the amino acids.

scholarly journals A kinetic study of rabbit muscle pyruvate kinase

1973 ◽  
Vol 131 (2) ◽  
pp. 223-236 ◽  
Author(s):  
S. Ainsworth ◽  
N. Macfarlane
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Study ◽  
Pyruvate Kinase ◽  
Random Order ◽  
Experimental Results ◽  
Rabbit Muscle ◽  
Dead End ◽  
Inhibition Constants ◽  
Muscle Pyruvate Kinase ◽  
Kinetics Of

The paper reports a study of the kinetics of the reaction between phosphoenolpyruvate, ADP and Mg2+ catalysed by rabbit muscle pyruvate kinase. The experimental results indicate that the reaction mechanism is equilibrium random-order in type, that the substrates and products are phosphoenolpyruvate, ADP, Mg2+, pyruvate and MgATP, and that dead-end complexes, between pyruvate, ADP and Mg2+, form randomly and exist in equilibrium with themselves and other substrate complexes. Values were determined for the Michaelis, dissociation and inhibition constants of the reaction and are compared with values ascertained by previous workers.

scholarly journals Inhibitory effect of Zn2+ on rabbit muscle pyruvate kinase and reactivation by histidine.

1981 ◽  
Vol 27 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Nanaya TAMAKI ◽  
Tatsuhiko IKEDA ◽  
Keiko KIMURA ◽  
Sachiko MORIOKA
Keyword(s):  
Pyruvate Kinase ◽  
Inhibitory Effect ◽  
Rabbit Muscle ◽  
Muscle Pyruvate Kinase
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