Discovery of Selective Pituitary Adenylate Cyclase 1 Receptor (PAC1R) Antagonist Peptides Potent in a Maxadilan/PACAP38-Induced Increase in Blood Flow Pharmacodynamic Model.

Inhibition of the pituitary adenylate cyclase 1 receptor (PAC1R) is a novel mechanism that could be used for abortive treatment of acute migraine. Our research began with comparative analysis of known PAC1R ligand scaffolds, PACAP38 and Maxadilan, which resulted in the selection of des(24-42) Maxadilan, , as a starting point. C-terminal modifications of improved the peptide metabolic stability and .

Agonistic Human Antibodies Binding to Lecithin-Cholesterol Acyltransferase Modulate High Density Lipoprotein Metabolism.

Drug discovery opportunities where loss-of-function alleles of a target gene link to a disease-relevant phenotype often require an agonism approach to up-regulate or re-establish the activity of the target gene. Antibody therapy is increasingly recognized as a favored drug modality due to multiple desirable pharmacological properties. However, agonistic antibodies that enhance the activities of the target enzymes are rarely developed because the discovery of agonistic antibodies remains elusive.

BacMam production of active recombinant lecithin-cholesterol acyltransferase: Expression, purification and characterization.

Lecithin-cholesterol acyltransferase (LCAT) is a key enzyme in the esterification of cholesterol and its subsequent incorporation into the core of high density lipoprotein (HDL) particles. It is also involved in reverse cholesterol transport (RCT), the mechanism by which cholesterol is removed from peripheral cells and transported to the liver for excretion. These processes are involved in the development of atherosclerosis and coronary heart disease (CHD) and may have therapeutic implications.

The high-resolution crystal structure of human LCAT.

LCAT is intimately involved in HDL maturation and is a key component of the reverse cholesterol transport (RCT) pathway which removes excess cholesterol molecules from the peripheral tissues to the liver for excretion. Patients with loss-of-function LCAT mutations exhibit low levels of HDL cholesterol and corneal opacity. Here we report the 2.

Anti-PCSK9 antibody pharmacokinetics and low-density lipoprotein-cholesterol pharmacodynamics in nonhuman primates are antigen affinity-dependent and exhibit limited sensitivity to neonatal Fc receptor-binding enhancement.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as an attractive therapeutic target for cardiovascular disease. Monoclonal antibodies (mAbs) that bind PCSK9 and prevent PCSK9:low-density lipoprotein receptor complex formation reduce serum low-density lipoprotein-cholesterol (LDL-C) in vivo. PCSK9-mediated lysosomal degradation of bound mAb, however, dramatically reduces mAb exposure and limits duration of effect.

Discovery of AMG 925, a FLT3 and CDK4 dual kinase inhibitor with preferential affinity for the activated state of FLT3.

We describe the structural optimization of a lead compound 1 that exhibits dual inhibitory activities against FLT3 and CDK4. A series of pyrido[4',3':4,5]pyrrolo[2,3-d]pyrimidine derivatives was synthesized, and SAR analysis, using cell-based assays, led to the discovery of 28 (AMG 925), a potent and orally bioavailable dual inhibitor of CDK4 and FLT3, including many FLT3 mutants reported to date. Compound 28 inhibits the proliferation of a panel of human tumor cell lines including Colo205 (Rb(+)) and U937 (FLT3(WT)) and induced cell death in MOLM13 (FLT3(ITD)) and even in MOLM13 (FLT3(ITD, D835Y)), which exhibits resistance to a number of FLT3 inhibitors currently under clinical development.

Discovery and optimization of a series of liver X receptor antagonists.

The present report describes our efforts to convert an existing LXR agonist into an LXR antagonist using a structure-based approach. A series of benzenesulfonamides was synthesized based on structural modification of a known LXR agonist and was determined to be potent dual liver X receptor (LXR α/β) ligands. Herein we report the identification of compound 54 as the first reported LXR antagonist that is suitable for pharmacological in vivo evaluation in rodents.

Discovery of a new binding mode for a series of liver X receptor agonists.

Structural modification of a series of dual LXRα/β agonists led to the identification of a new class of LXRβ partial agonists. An X-ray co-crystal structure shows that a representative member of this series, pyrrole 5, binds to LXRβ with a reversed orientation compared to 1.

A proprotein convertase subtilisin/kexin type 9 neutralizing antibody reduces serum cholesterol in mice and nonhuman primates.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates serum LDL cholesterol (LDL-C) by interacting with the LDL receptor (LDLR) and is an attractive therapeutic target for LDL-C lowering. We have generated a neutralizing anti-PCSK9 antibody, mAb1, that binds to an epitope on PCSK9 adjacent to the region required for LDLR interaction. In vitro, mAb1 inhibits PCSK9 binding to the LDLR and attenuates PCSK9-mediated reduction in LDLR protein levels, thereby increasing LDL uptake.

Molecular basis of PCSK9 function.

The LDL receptor (LDLr) inhibitor Proprotein Convertase Subtilisin Kexin type 9 (PCSK9) has emerged as a genetically validated target for lowering plasma LDL cholesterol levels. In 2007, PCSK9 was found to act as a chaperone that binds the LDLr, thereby targeting it for lysosomal degradation. The enzymatic activity of PCSK9 is not involved in that process, but rather permits proper intramolecular processing of PCSK9.

The crystal structure of PCSK9: a regulator of plasma LDL-cholesterol.

Proprotein convertase subtilisin kexin type 9 (PCSK9) has been shown to be involved in the regulation of extracellular levels of the low-density lipoprotien receptor (LDLR). Although PCSK9 is a subtilase, it has not been shown to degrade the LDLR, and its LDLR-lowering mechanism remains uncertain. Here we report the crystal structure of human PCSK9 at 2.

Novel inhibitors of hepatitis C virus RNA-dependent RNA polymerases.

Hepatitis C virus (HCV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma worldwide-and is the main cause of adult liver transplants in developed nations. We have identified a class of novel and specific inhibitors of HCV NS5B RNA-dependent RNA polymerase (RdRp) activity in vitro. Characterization of two such inhibitors, COMPOUND1 (5-(4-chlorophenylmethylene)-3-(benzenesulfonylamino)-4-oxxo-2-thionothiazolidine) and COMPOUND2 (5-(4-bromophenylmethylene)-3-(benzenesulfonylamino)-4-oxxo-2-thionothiazolidine), is reported here.

SAR and mode of action of novel non-nucleoside inhibitors of hepatitis C NS5b RNA polymerase.

Novel non-nucleoside inhibitors of the HCV RNA polymerase (NS5b) with sub-micromolar biochemical potency have been identified which are selective for the inhibition of HCV NS5b over other polymerases. The structures of the complexes formed between several of these inhibitors and HCV NS5b were determined by X-ray crystallography, and the inhibitors were found to bind in an allosteric binding site separate from the active site. Structure-activity relationships and structural studies have identified the mechanism of action for compounds in this series, several of which possess drug-like properties, as unique, reversible, covalent inhibitors of HCV NS5b.

Hepatocyte growth factor is a preferred in vitro substrate for human hepsin, a membrane-anchored serine protease implicated in prostate and ovarian cancers.

Hepsin is a membrane-anchored, trypsin-like serine protease with prominent expression in the human liver and tumours of the prostate and ovaries. To better understand the biological functions of hepsin, we identified macromolecular substrates employing a tetrapeptide PS-SCL (positional scanning-synthetic combinatorial library) screen that rapidly determines the P1-P4 substrate specificity. Hepsin exhibited strong preference at the P1 position for arginine over lysine, and favoured threonine, leucine or asparagine at the P2, glutamine or lysine at the P3, and proline or lysine at the P4 position.

Infections and severe sepsis in solid-organ transplant patients admitted from a university-based ED.

The objective was to provide a descriptive analysis of infectious processes in transplant patients admitted from the emergency department (ED). A database of all adult transplant patients at a university medical center was cross-referenced with a computerized record of all ED visits over an 18-month period. ED charts, inpatient records, and microbiology data were retrospectively reviewed.