Driven by chemistry but increasingly guided by pharmacology and the clinical sciences, drug research has contributed more to the progress of medicine during the past century than any other scientific factor. The advent of molecular biology and, in particular, of genomic sciences is having a deep impact on drug discovery. Recombinant proteins and monoclonal antibodies have greatly enriched our therapeutic armamentarium. Genome sciences, combined with bioinformatic tools, allow us to dissect the genetic basis of multifactorial diseases and to determine the most suitable points of attack for future medicines, thereby increasing the number of treatment options. The dramatic increase in the complexity of drug research is enforcing changes in the institutional basis of this interdisciplinary endeavor. The biotech industry is establishing itself as the discovery arm of the pharmaceutical industry. In bridging the gap between academia and large pharmaceutical companies, the biotech firms have been effective instruments of technology transfer.

/pdf/drug-discovery-a-historical-perspective-50rbwd8ekh.pdf

Drug Discovery: A Historical Perspective

https://www.cell.com/cell/pdf/0092-8674(94)90570-3.pdf

RAFT1: a mammalian protein that binds to FKBP12 in a rapamycin-dependent fashion and is homologous to yeast TORs.

Suppression of allograft rejection is central to successful organ transplantation; thus, immunosuppressive agents are crucial for successful allograft function. Immunosuppressive drugs are used for induction (intense immunosuppression in the initial days after transplantation), maintenance, and reversal of established rejection. This review considers the use of immunosuppressive drugs in organ transplantation, focusing on renal transplantation.

https://www.nejm.org/doi/pdf/10.1056/NEJMra033540

Immunosuppressive Drugs for Kidney Transplantation

THE structurally novel macrolide FK506 (refs 1,2) has recently been demonstrated to have potent immunosuppressive activity3–7 at concentrations several hundredfold lower than cyclosporin A (CsA). Cyclosporin A, a cyclic peptide, has found widespread clinical use in the prevention of graft rejection following bone marrow and organ transplantation8. The mechanisms of immunosuppression mediated by FK506 and CsA appear to be remarkably similar, suggesting that these unrelated structures act on a common receptor or on similar molecular targets, perhaps the CsA receptor, cyclophilin9–11, which has recently been shown by Fischer etal.12 and Takahashi etal.13 to have cis–trans peptidyl-prolyl isomerase activity. We have prepared an FK506 affinity matrix and purified a binding protein for FK506 from bovine thymus and from human spleen. This FK506-binding protein (FKBP) has a relative molecular mass (Mr) of ∼14,000(14K), a pi of 8.8–8.9, and does not cross-react with antisera against cyclophilin. The first 40 N-terminal residues of the bovine and 16 residues of the human FKBP were determined; the 16-residue fragments are identical to each other and unrelated to any known sequences. This protein catalyses the cis–trans isomerization of the proline amide in a tetrapeptide substrate and FK506 inhibits the action of this new isomerase. The FKBP and cyclophilin appear to be members of an emerging class of novel proteins that regulate T cell activation and other metabolic processes, perhaps by the recognition (and possibly the isomerization) of proline-containing epitopes in target proteins.

A receptor for the immunosuppressant FK506 is a cis-trans peptidyl-prolyl isomerase.

The immuno-pharmacological profile of a novel immunosuppressive agent, FK-506 produced by a streptomycete, is presented here. We proceeded to test the effect of the agent on various in vitro immune systems. It showed that mixed lymphocyte reaction, cytotoxic T cell generation, the production of T cell-derived soluble mediators such as interleukin 2 (IL-2), interleukin 3 and gamma-interferon and the expression of the IL-2 receptor were suppressed by this agent. The IC50 values of FK-506 and ciclosporin (CS) in all tests were approximately 0.1nM and 10nM, respectively. Therefore, the novel agent, FK-506 suppressed in vitro immune systems at about hundred times lower concentration than CS.

https://www.jstage.jst.go.jp/article/antibiotics1968/40/9/40_9_1249/_pdf

FK-506, a novel immunosuppressant isolated from a Streptomyces. II. Immunosuppressive effect of FK-506 in vitro.

A novel human leukocyte elastase (HLE) inhibitor, FR901451 was discovered in the fermentation broth of a bacteria. The bacteria was identified as Flexibacter sp. No. 758. FR901451 has a molecular weight of 1269 and a molecular formula of C60H79N13O18. The mode of inhibition against HLE is competitive, with a Ki value of 9.8 x 10(-9) M.

FR901451, a novel inhibitor of human leukocyte elastase from Flexibacter sp. I. Producing organism, fermentation, isolation, physico-chemical and biological properties.

WSl358Al (FR104007) and Bl (FR104008), new potent inhibitors of renal dehydropeptidase, were isolated from the culture broth of strain No. 1358 which was identified as Streptomyces parvulus subsp. In vitro inhibitory activities (IC50 value) of WSl358Al and Bl against porcine renal DHP were 3 and 600 nM, respectively.

Studies on new dehydropeptidase inhibitors

WF14861, a novel cathepsins B and L inhibitor, was obtained from the culture mycelium of a fungus strain Colletotrichum sp. No. 14861. Spectroscopic analysis showed that WF14861 consisted of trans-epoxysuccinic acid, L-tyrosine and spermidine, WF14861 inhibited cathepsins B and L selectively.

WF14861, a new cathepsins B and L inhibitor produced by Colletotrichum sp. I. Taxonomy, production, purification and structure elucidation.

Strain of Streptomyces for the production of tricyclo compounds

WF14865A and B, novel cathepsins B and L inhibitors, were produced and isolated separately from the culture mycelium of a fungal strain Aphanoascus fulvescens No. 14865. Spectroscopic analysis revealed that both WF 14865A and B were composed of trans-epoxysuccinyl moieties, 1-H-imidazole-2-ylamine, and isoleucine or leucine. These compounds inhibited human cathepsins B and L with IC50 values in the range of 8.4-72 nM in vitro. Though their in vitro properties were typical as trans-epoxysuccmyl type inhibitors, they exerted strong bone resorption inhibitory effects in low-calcium-diet-fed mouse model at 3.2-10mg/kg.

Hiroshi Hatanaka

Papers

FR901451, a novel inhibitor of human leukocyte elastase from Flexibacter sp. I. Producing organism, fermentation, isolation, physico-chemical and biological properties.

Studies on new dehydropeptidase inhibitors

WF14861, a new cathepsins B and L inhibitor produced by Colletotrichum sp. I. Taxonomy, production, purification and structure elucidation.

Strain of Streptomyces for the production of tricyclo compounds

WF14865A and B, new cathepsins B and L inhibitors produced by Aphanoascus fulvescens. I. Taxonomy, production, purification and biological properties.