ABSTRACT
Interleukin-2 inducible T-cell kinase (Itk) plays a role in T-cell functions, and its inhibition potentially represents an attractive intervention point to treat autoimmune and allergic diseases. Herein we describe the discovery of a series of potent and selective novel inhibitors of Itk. These inhibitors were identified by structure-based design, starting from a fragment generated de novo, the 3-aminopyrid-2-one motif. Functionalization of the 3-amino group enabled rapid enhancement of the inhibitory activity against Itk, while introduction of a substituted heteroaromatic ring in position 5 of the pyridone fragment was key to achieving optimal selectivity over related kinases. A careful analysis of the hydration patterns in the kinase active site was necessary to fully explain the observed selectivity profile. The best molecule prepared in this optimization campaign, 7v, inhibits Itk with a K(i) of 7 nM and has a good selectivity profile across kinases.
Subject(s)
Drug Design , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyridones/chemistry , Pyridones/pharmacology , Adenosine Triphosphate/metabolism , Catalytic Domain , Hydrogen Bonding , Maleimides/chemistry , Models, Molecular , Protein Kinase Inhibitors/chemical synthesis , Protein-Tyrosine Kinases/chemistry , Protein-Tyrosine Kinases/metabolism , Pyridones/chemical synthesis , Structure-Activity Relationship , Substrate SpecificityABSTRACT
The identification of a novel series of Aurora kinase inhibitors and exploitation of their SAR is described. Replacement of the initial quinazoline core with a pyrimidine scaffold and modification of substituents led to a series of very potent inhibitors of cellular proliferation. MK-0457 (VX-680) has been assessed in Phase II clinical trials in patients with treatment-refractory chronic myelogenous leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) containing the T315I mutation.
Subject(s)
Piperazines/chemistry , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/antagonists & inhibitors , Aurora Kinases , Cell Line, Tumor , Computer Simulation , Crystallography, X-Ray , Drug Design , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Mutant Proteins/antagonists & inhibitors , Mutant Proteins/metabolism , Piperazines/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/metabolism , Structure-Activity RelationshipABSTRACT
Nicotine replacement therapies (NRT) have limited success in smoking cessation. The efficacy of nicotine may be compromised by its main metabolite, cotinine. An anti-cotinine vaccine to remove this antagonism could enhance the efficacy of NRT. We show that cotinine is a weak nicotinic agonist and decreases responses to nicotine, consistent with antagonism through receptor desensitisation. trans-4-Thiol cotinine was coupled to tetanus toxoid, and rats immunised repeatedly. Vaccination raised antibodies specific for cotinine that do not recognise other metabolites or nicotine. Increased serum cotinine concentrations following nicotine administration indicate sequestration of cotinine by antibodies, encouraging further evaluation of this vaccine in behavioural models of nicotine addiction and relapse.
Subject(s)
Cotinine/antagonists & inhibitors , Cotinine/immunology , Nicotine/administration & dosage , Smoking Cessation/methods , Vaccines, Conjugate/isolation & purification , Animals , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Cotinine/metabolism , Dopamine/metabolism , Humans , In Vitro Techniques , Male , Nicotine/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Nicotinic/drug effects , Receptors, Nicotinic/metabolismABSTRACT
The synthesis of the Fmoc-protected C-glycosyl tyrosines 1 and 2, together with two other related C-glycosyl tyrosines, has been achieved. Key reactions involved (i) the reaction of a glycal with an organozinc reagent (carrying an aryl iodide function) in the presence of a Lewis acid to establish the C-glycosyl linkage and (ii) subsequent cross coupling of the aryl iodide to an alanyl zinc reagent (in the presence of a Pd(0) catalyst) to complete the construction of the alpha-amino acid moiety. Using solid-phase peptide synthesis methods, two units of the mannosyl derivative 1 (shown as L-Tyr[C-Ac(4)-alpha-D-Man]) have been incorporated (with four units of glycine) into the linear hexapeptide 3 which was then converted to the C(2)-symmetric cyclic oligopeptide 4.
