Mechanism of allosteric activation of glycogen phosphorylase probed by the reactivity of essential arginine residues. Identification of an arginine residue involved in the binding of glucose 1-phosphate

Biochemistry ◽  
1981 ◽  
Vol 20 (8) ◽  
pp. 2354-2360 ◽  
Author(s):  
Bernard Vandenbunder ◽  
Marc Dreyfus ◽  
Olivier Bertrand ◽  
May J. Dognin ◽  
Lise Sibilli ◽  
...  
Keyword(s):  
Glycogen Phosphorylase ◽  
Arginine Residue ◽  
Allosteric Activation ◽  
Arginine Residues

scholarly journals Evidence for the importance of arginine residues in pig kidney alkaline phosphatase

1979 ◽  
Vol 181 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M N Woodroofe ◽  
P J Butterworth
Keyword(s):  
Alkaline Phosphatase ◽  
Active Site ◽  
Competitive Inhibitor ◽  
Arginine Residue ◽  
Pig Kidney ◽  
Close Proximity ◽  
Arginine Residues ◽  
Km Value ◽  
Uncompetitive Inhibitor ◽  
Kidney Alkaline Phosphatase

The arginine-specific reagents 2,3-butanedione and phenylglyoxal inactivate pig kidney alkaline phosphatase. As inactivation proceeds there is a progressive fall in Vmax. of the enzyme, but no demonstrable change in the Km value for substrate. Pi, a competitive inhibitor, and AMP, a substrate of the enzyme, protect alkaline phosphatase against the arginine-specific reagents. These effects are explicable by the assumption that the enzyme contains an essential arginine residue at the active site. Protection is also afforded by the uncompetitive inhibitor NADH through a partially competive action against the reagents. Enzyme that has been exposed to the reagents has a decreased sensitivity to NADH inhibition. It is suggested that an arginine residue is important for NADH binding also, although this residue is distinct from that at the catalytic site. The protection given by NADH against loss of activity is indicative of the close proximity of the active and NADH sites.

Identification of the molecular trigger for allosteric activation in glycogen phosphorylase

1994 ◽  
Vol 1 (5) ◽  
pp. 327-333 ◽  
Author(s):  
Michelle F. Browner ◽  
David Hackos ◽  
Robert Fletterick
Keyword(s):  
Glycogen Phosphorylase ◽  
Allosteric Activation

scholarly journals Inactivation of aspartyl proteinases by butane-2,3-dione. Modification of tryptophan and tyrosine residues and evidence against reaction of arginine residues

1981 ◽  
Vol 193 (1) ◽  
pp. 55-65 ◽  
Author(s):  
J C Gripon ◽  
T Hofmann
Keyword(s):  
Amino Acid ◽  
Arginine Residue ◽  
Penicillium Roqueforti ◽  
Amino Acid Residues ◽  
Prolonged Incubation ◽  
Tyrosine Residues ◽  
Arginine Residues ◽  
Structural Breakdown ◽  
Methionine Residues ◽  
Aspartyl Proteinases

Butane-2,3-dione inactivates the aspartyl proteinases from Penicillium roqueforti and Penicillium caseicolum, as well as pig pepsin, penicillopepsin and Rhizopus pepsin, at pH 6.0 in the presence of light but not in the dark. The inactivation is due to a photosensitized modification of tryptophan and tyrosine residues. In the dark none of the amino acid residues, not even arginine residues, is modified even after several days. In the light one arginine residue in pig pepsin is lost at a rate that is comparable with the rate of inactivation; however, the loss of the single arginine residue in the aspartyl proteinase of P. roqueforti and the second arginine residue of pig pepsin is slower than the loss of activity; penicillopepsin is devoid of arginine. Loss of most of the activity is accompanied by the following amino acid losses: P. roqueforti aspartyl proteinase, about two tryptophan and six tyrosine residues; penicillopepsin, about two tryptophan and three tyrosine residues; pig pepsin, about four tryptophan and most of the tyrosine residues. Modification of histidine residues was too slow to contribute to inactivation. None of the other residues, including half-cystine and methionine residues (when present), was modified even after prolonged incubation. The inactivation of P. roqueforti aspartyl proteinase and pig pepsin appears due to non-specific modification of several residues. With penicillopepsin, however, the reaction is more limited and initially affects only those tryptophan and tyrosine residues that lie in the active-site groove. In the presence of pepstatin the rate of inactivation is considerably diminished. After prolonged reaction a general structural breakdown occurs.

scholarly journals An Isozyme-specific Redox Switch in Human Brain Glycogen Phosphorylase Modulates Its Allosteric Activation by AMP

2016 ◽  
Vol 291 (46) ◽  
pp. 23842-23853 ◽  
Author(s):  
Cécile Mathieu ◽  
Romain Duval ◽  
Angélique Cocaign ◽  
Emile Petit ◽  
Linh-Chi Bui ◽  
...  
Keyword(s):  
Human Brain ◽  
Glycogen Phosphorylase ◽  
Allosteric Activation ◽  
Brain Glycogen ◽  
Redox Switch

scholarly journals Inactivation of glutamate dehydrogenase and glutamate synthase from Bacillus megaterium by phenylglyoxal, butane-2,3-dione and pyridoxal 5′-phosphate

1978 ◽  
Vol 173 (1) ◽  
pp. 53-58 ◽  
Author(s):  
I A Hemmilä ◽  
P I Mäntsälä
Keyword(s):  
Enzyme Activity ◽  
Glutamate Dehydrogenase ◽  
Bacillus Megaterium ◽  
Glutamate Synthase ◽  
Complete Loss ◽  
Borate Buffer ◽  
Arginine Residue ◽  
Complete Protection ◽  
Complete Inactivation ◽  
Arginine Residues

Reaction of phenylglyoxal with glutamate dehydrogenase (EC 1.4.1.4), but not with glutamate synthase (EC 2.6.1.53), from Bacillus megaterium resulted in complete loss of enzyme activity. NADPH alone or together with 2-oxoglutarate provided substantial protection from inactivation by phenylglyoxal. Some 2mol of [14C]Phenylglyoxal was incorporated/mol of subunit of glutamate dehydrogenase. Addition of 1mM-NADPH decreased incorporation by 0.7mol. The Ki for phenylglyoxal was 6.7mM and Ks for competition with NADPH was 0.5mM. Complete inactivation of glutamate dehydrogenase by butane-2,3-dione was estimated by extrapolation to result from the loss of 3 of the 19 arginine residues/subunit. NADPH, but not NADH, provided almost complete protection against inactivation. Butane-2,3-dione had only a slight inactivating effect on glutamate synthase. The data suggest that an essential arginine residue may be involved in the binding of NADPH to glutamate dehydrogenase. The enzymes were inactivated by pyridoxal 5′-phosphate and this inactivation increased 3–4-fold in the borate buffer. NADPH completely prevented inactivation by pyridoxal 5′-phosphate.

Effect of Modification of Arginine Residues on the Activity of Soybean Lipoxygenase-1

1995 ◽  
Vol 50 (1-2) ◽  
pp. 37-44 ◽  
Author(s):  
Kenji Matsui ◽  
Hiroyuki Shinta ◽  
Tadahiko Kajiwara ◽  
Akikazu Hatanaka
Keyword(s):  
Linoleic Acid ◽  
Salt Concentration ◽  
Enzyme Reaction ◽  
Arginine Residue ◽  
Sodium Borate ◽  
Chemical Modifier ◽  
Soybean Lipoxygenase ◽  
Assay Condition ◽  
Product Specificity ◽  
Arginine Residues

Abstract Arginine residues of soybean lipoxygenase-1 was modified with an arginine-directed chemical modifier, 2,3-butanedione. Although inactivation was not visible if the enzyme reaction was monitored under the standard assay condition (83.3 μᴍ linoleic acid dispersed in 200 mᴍ sodium borate, pH 9.0), rapid inactivation was observed with 5 mᴍ sodium borate, pH 8.0. The inactivation was protected by the addition of a substrate, linoleic acid, in the modification mixture. Kinetic analyses indicated that one arginine residue accounted for the inactivation. Enzymological analyses showed that the modification narrowed the pH-activity profile of L-1 and made L-1 sensitive to salt concentration of the assay solution. Strong inactivation by modification was found at low salt concentration and low pH. This was not due to a physical change of the linoleic acid. On the other hand, product specificity of L-1 was not altered after modification. Taken together, the modified arginine residue(s) was thought to be not essential to the catalysis but have an important role in supporting an ideal electrostatic interaction within L-1 and/or between L-1 and a substrate even in sub-optimal reaction conditions.

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