ABSTRACT
A research program has applied the tools of synthetic organic chemistry to systematically modify the structure of DNA and RNA oligonucleotides to learn more about the chemical principles underlying their ability to store and transmit genetic information. Oligonucleotides (as opposed to nucleosides) have long been overlooked by synthetic organic chemists as targets for structural modification. Synthetic chemistry has now yielded oligonucleotides with 12 replicatable letters, modified backbones, and new insight into why Nature chose the oligonucleotide structures that she did.
Subject(s)
DNA/chemistry , Molecular Biology/trends , Nucleic Acids/chemistry , Oligonucleotides/chemical synthesis , Catalysis , Codon , Molecular Structure , Nucleic Acids/chemical synthesis , Oligonucleotides/chemistry , Phosphates/chemistry , Sulfones/chemistryABSTRACT
Structure-activity relationships of a lead hydroxamic acid inhibitor of recombinant human stromelysin were systematically defined by taking advantage of a concise synthesis that allowed diverse functionality to be explored at each position in a template. An ex vivo rat model and an in vivo rabbit model of stromelysin-induced cartilage degradation were used to further optimize these analogs for oral activity and duration of action. The culmination of these modifications resulted in CGS 27023A, a potent, orally active stromelysin inhibitor that blocks the erosion of cartilage matrix.
Subject(s)
Cartilage/metabolism , Hydroxamic Acids , Matrix Metalloproteinase Inhibitors , Protease Inhibitors/pharmacology , Pyrazines , Administration, Oral , Animals , Binding Sites , Cartilage/drug effects , Chromatography, High Pressure Liquid , Enzyme-Linked Immunosorbent Assay , Humans , In Vitro Techniques , Kinetics , Models, Chemical , Rabbits , Rats , Recombinant Proteins/antagonists & inhibitors , Structure-Activity Relationship , Substance P/metabolism , SulfonamidesSubject(s)
Cartilage, Articular/pathology , Hydroxamic Acids , Metalloendopeptidases/antagonists & inhibitors , Osteoarthritis/prevention & control , Protease Inhibitors/therapeutic use , Proteoglycans/metabolism , Pyrazines , Animals , Cartilage, Articular/metabolism , Hindlimb/pathology , Joints/pathology , Male , Osteoarthritis/pathology , Protease Inhibitors/administration & dosage , Rabbits , SulfonamidesABSTRACT
A potent macrocyclic inhibitor of neutral endopeptidase (NEP) 24.11 was designed using a computer model of the active site of thermolysin. This 10-membered ring lactam represents a general mimic for any hydrophobic dipeptide in which the two amino acid side chains bind to an enzyme in a contiguous orientation. The parent 10-membered ring lactam was synthesized and exhibited excellent potency as an NEP 24.11 inhibitor (IC50 = 3 nM). In order to improve oral bioavailability, various functionality was attached to the macrocycle. These modifications lead to CGS 25155, an orally active NEP 24.11 inhibitor that slows down the degradation of the cardiac hormone atrial natriuretic factor, producing a lowering of blood pressure in the DOCA-salt rat model of hypertension.
Subject(s)
Antihypertensive Agents/chemical synthesis , Drug Design , Hydroxyproline/analogs & derivatives , Neprilysin/antagonists & inhibitors , Peptides, Cyclic/chemical synthesis , Administration, Oral , Amino Acid Sequence , Animals , Antihypertensive Agents/pharmacokinetics , Antihypertensive Agents/therapeutic use , Atrial Natriuretic Factor/blood , Binding Sites , Biological Availability , Computer Simulation , Crystallography, X-Ray , Hydroxyproline/chemical synthesis , Hydroxyproline/pharmacokinetics , Hydroxyproline/therapeutic use , Hypertension/blood , Hypertension/chemically induced , Hypertension/drug therapy , Models, Molecular , Molecular Sequence Data , Molecular Structure , Neprilysin/metabolism , Peptides, Cyclic/pharmacokinetics , Peptides, Cyclic/therapeutic use , Rats , Thermolysin/chemistryABSTRACT
A detailed study of the chemical behavior of modern catalysts (here, exemplified by dehydrogenases dependent on NAD+) allows us to construct models that distinguish between selected and drifting behaviors in biological macromolecules. These models enable us to manipulate rationally the properties of enzymes, here to design an "acetaldehyde reductase" dependent on NAD+ that is faster than any given us by nature. When applied to the origin of protein catalysis, models that explain the structures of ribo-cofactors (e.g., NAD+) must postulate a metabolically complex breakthrough organism. This means that: (1) The view from the present day back to the truly primeval organism is obscured; it is futile to try to deduce the detailed structure of the first life by examining the behaviors of modern organisms. (2) Riboorganisms dominated life on earth for a long time before translation evolved; indeed, fossils of riboorganisms might already be known. (3) Using organic synthesis, we have expanded the number of bases available for making RNA and making accessible RNA molecules that are likely to be intrinsically better catalysts.
