Effects of anions on a monomeric and a dimeric arginine kinase

Abstract

1. Some effects of anions on the rates of phosphoarginine synthesis by monomeric (lobster) and by dimeric (Holothuria forskali) arginine kinases are reported. 2. As with creatine kinase, acetate ions activate both enzymes: C1-was also found to activate both although this was an inhibitor of creatine kinase. 3. NO3-inhibits the lobster enzyme.Inhibition is of the mixed type with respect to MgATP. K1 >K1' and K, >IK.' indicating that the presence of N03-promotes the binding of substrate and vice versa. 4. NO3-alone has no effect on the difference spectrum of the lobster enzyme but in the presence of arginine, MgATP, MgADP, MgAMP or MgIDP the difference spectrum is greatly enhanced. A profound effect on the ionization state oftyrosine residues is inferred. 5. With the Holothuria enzymelow concentrations ofNO3-activate in a manner that iscompetitive with arginine. Higher concentrations cause inhibition of the mixed type with respect to arginine in a similar manner to that found with MgATP for the lobster kinase. 6. Ofa range of anions tested only NO3-and NO2-enhanced the inhibition of enzyme activity by MgADP, indicating the formation of a pseudo-transition-state dead-end complex, enzyme-arginine-NO3-MgADP. The effect was essentially independent of temperature with the Holothuria enzyme, but with the lobster enzyme was much less marked and temperature dependent. The difference may reflect the different stabilities of the monomer and dimer enzymes, although with neither arginine kinase is the stabilization of the dead-end complex as marked as is found with creatinine kinase.Mitner-White & Watts (1971) found tha-t a strong inhibition of rabbit muscle creatine kinase was caused by NO3-ions in the presence of the dead-end complex, creatine-enzyme-MgADP. It was suggested that the planar anion acted by mimicking the transferable phosphoryl group in a transition stage in the reaction and thereby locked the two substrates together. The effectiveness of other anions as inhibitors was related to the extent to which they could behave like NO3-ions. Detailed protonrelaxation-rate studies by Cohn and co-workers confirmed and extended this hypothesis (McLaughlin & Cohn, 1972;, and recently further support has come from investigations with the fluorescent probe 8-anilinonaphthalene-1-sulphonate (McLaughlin, 1974 The work reported below was designed to discover whether arginine kinases were inhibited by low concentrations of anions, lOOmm and less, in a similar manner to the creatine kinases. With two arginine kinases, the monomeric form from the lobster, Homarus vulgaris, and the dimeric form from the sea cucumber, Holothuria forskali, evidence has been presented to indicate that stabilization of a substrate dead-end complex could occur. However, the picture is complicated by additional protein-ion interactions. Materials and MethodsADP (disodium salt) and ATP (disodium salt) were

Characterization and distribution of arginine kinase in the tissues of the scorpion, Palamneus phipsoni

“…The activity in the presence of nitrate was only 76% of that with acetate ( Table 1). This is probably explained by the observations of Anosike and Watts ( 1975) that acetate is an activator and nitrate is an inhibitor of lobster muscle arginine kinase. Calcium acetate was only one-fourth as effective as Mg acetate in activating the enzyme (Table 1 ).…”

Alkaline unfolding and salt-induced folding of arginine kinase from shrimp Feneropenaeus chinensis under high pH conditions

“…These include the monomer form with a mass of approximately 40 kDa, the homodimer of 80 kDa, and a highly molecular weight form of between 150 and 160 kDa, etc. [17][18][19][20] of AK in energy storage in invertebrates where it is functionally analogous to creatine kinase found in vertebrate, many studies have reported the purification, characterization, properties and unfolding of AK [21][22][23][24]. However, very few authors concentrated on the folding behavior of AK.…”

Interaction in vitro of scallop muscle arginine kinase with filamentous actin

“…4). The planar anion, NO,, inhibits AK by stabilizing the dead-end complex, argi-A B nine-AK-Mg2+-ADP (Anosike and Watts, 1975). In the presence of the ligands, arginine, Mg2+-ADP and NO;, the binding of AK to scallop F-actin was inhibited, as shown by the shift of the binding curve to the right and threefold increase in apparent Kd (Fig.…”

“…The exaggerated conformational changes that are associated with the stabilization of the abortive arginine -AK-Mg*+-ADP complex by NO; (Anosike and Watts, 1975) might prevent the interaction of AK with actin. Alterations in glycolytic enzyme binding to contractile proteins in the presence of metabolites have been reported (Arnold and Pette, 1970;Yasikowa et al, 1990).…”