An ICof 200 M. Attaching an more phenethyl group to the adenine ring (69) resulted in increased potency (IC50 = 30 M). At 100 M, compound 34 was selective over rabbit muscle PGK. Compound 34 was also tested against BSF T. brucei brucei and T. brucei rhodesiense. Screens against each subspecies gave an EC50 of 20 M, and 40 M against murine fibroblasts, representing a 2-fold selectivity.105 five.three.1.four. Hexokinase. As a third instance of a carbohydrate MI-503 kinase targeted for inhibitor discovery, the T. brucei hexokinase is only 37 related to the human homologue, suggesting the possibility of selective inhibitor design.8 Phosphorylation of glucose to glucose-6-phosphate is catalyzed by hexokinase, and several research have shown that analogues of glucose, like glucosamine106 and 2-C-hydroxymethyl glucose107 derivatives, inhibit the reaction. Considering that glucose-6-phosphate has affinity toward the active web site of T. brucei hexokinase, Willson et al. tested several glucose-6-phosphate analogues against T. brucei hexokinase. Compounds 35 and 36, shown in Figure 9, showed weak inhibition against T. brucei hexokinase, with 75 inhibition at 3 mM for 35 and 60 inhibition at 0.2 mM for 36.Figure 9. Glucose-6-phosphate derivatives tested against T. brucei hexokinase.Figure eight. Adenosine derivatives tested against TbPGK and T. brucei.5.3.two. Trypanosoma cruzi. Protein kinase activity in T. cruzi has been studied because the late 1970s. It was found that T. cruzi’s protein kinase activity PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21193451 was independent of cyclic nuleotides and stimulated as much as 4-fold by unique nucleosides.109 Inosine stimulated protein kinase activity at low concentration, and adenosine showed maximal stimulation at 0.1 mM.109 Deoxyadenosines inhibited protein kinase activity in T. cruzi and T. gambiense; 2 deoxyadenosine (37, Figure ten) inhibited protein kinase activity by 30 and three deoxyadenosine (38) by 75 . Both deoxyadenosides are competitive inhibitors of ATP (Ki = 0.11 mM and 0.eight mM, respectively).109 5.three.two.1. Arginine Kinase. Arginine kinase belongs towards the household of guanidine kinases. The guanidine kinases catalyze Nphosphorylated guanidino compounds by the reversible transferdx.doi.org/10.1021/cr500197d | Chem. Rev. 2014, 114, 11280-Chemical ReviewsReviewFigure 10. General protein kinase inhibitors in T. cruzi.of an ATP phosphoryl group to a guanidino acceptor within the enzyme. Phosphoarginine plays an essential part as an energy reserve resulting from the high-energy phosphate transfer when a renewal of ATP is required.110 A correlation among enzyme activity, nutrient availability, and cell density suggests that arginine kinases function as a regulator of power reserves under starvation tension situations.111 T. cruzi arginine kinase is inhibited at 10 mM by the arginine analogues, agmatine (39) to 79.three , canavanine (40) to 54.6 , nitroargine (41) to 52.6 , and homoarginine (42) to 38.two (Figure 11). Moreover,Figure 11. Inhibitors of arginine kinase in T. cruzi.canavanine and homoarginine inhibited the cell growth of epimastigotes of T. cruzi by 79.7 and 55.eight at a ten mM drug concentration, and their arginine kinase Ki values have been calculated to become 7.55 and 6.02 mM, respectively. These outcomes suggest inhibition of cell growth mediated by the inhibition on the parasite’s arginine kinase, even though the extraordinarily low potency of these inhibitors leaves room for more study to confirm this.188.8.131.52. Phosphofructokinase. Phosphofructokinase (PFK) has lately been identified to.