STRUCTURE AND PROPERTIES OF PROPROTEIN CONVERTASE INHIBITORS
V. K. Kibirev, T. V. Osadchuk
This review is devoted to structure and properties of proprotein convertases (PCs), the intracellular Ca2+-dependent serine endoproteases of mammalia, that play the essential role in the processing of inactive protein precursors and their transforming into bioactive mature products. PCs are also implicated in development of a great variety of diseases including bacterial or viral infections and such pathologies as cancer, Alzheimer’s disease, obesity and so on. Owing to these findings, PCs are considered as promising targets for design of their inhibitors and development of new potential therapeutic agents.
Only several endogenous protein inhibitors are identified now for PCs: pro7B2 (Proprotein 7B2), the specific chaperon of PC2, granine-like precursor of neuroendocrine protein proSAAS, the selective ligand of PC1, and serpin Spn4A (Serine Proteinase Inhibitor) of Drosophila melanogaster that inhibits PC2 and furin. By the methods of site-directed mutagenesis, the bioengineered inhibitors of PCs were also designed. Structures and properties of protein or peptide fragments as inhibitors of PCs were also discussed. Particularly, the properties of polyarginines and small peptides containing pseudopeptide bond at the scissile site a suitable peptide substrate were described.
The inhibitory activity of non-peptide compounds such as derivatives of andrographolid from Andrographis paniculata (Ki = 2.6–200 µM against furin), certain complexes of pyridine analogs with ions of Cu2+ or Zn2+ inhibiting furin with IC50 = 5–10 µM, derivatives of 2,5–dideoxystreptamine containing several guanidine groups (Ki = 6–812 nM for furin) and also a number of dicoumarols (Ki = 1–185 µM against furin) and some flavonoids (with Ki = 5–230 µM for furin) were reflected in the article. The effects of enediynyl-amino acids derivatives or their peptides (Ki ? 40 nM against furin) were considered. Inhibition of PC2 by N-acylated bicyclic guanidines (Ki = 3.3–10 µM) or derivatives of pyrrolidin bispyperazines (Ki = 0.54–10 µM) are considered too.
Some of synthesized derivatives may serve as lead compounds for design of the specific inhibitors for individual PCs.
Key words: proprotein convertases, proteinase inhibitors, protein and bioengineered inhibitors, peptide or pseudopeptide inhibitors, non-peptide inhibitors.
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© The Ukrainian Biochemical Journal