PCSK9

Function

PCSK9 or Proprotein Convertase Subtilisin/Kexin type 9 is a proteinase which is part of the cholesterol synthesis^[1]. PCSK9 undergoes autocatalysis producing an active enzyme from its precursor. PCSK9 binds to EGF-A domain of the LDL receptor (LDLR) inducing its degradation.

Relevance

Low levels of LDL receptor are a cause of hypercholesterolemia since LDLR removes LDL cholesterol from the blood. Thus PCSK9 is an important drug target as its level affects the amount of cholesterol in blood^[2]. Inhibition of PCSK9 results in increased pathogen lipid clearance, decreased inflammatory response and improved septic shock outcome^[3].

3D structures of PCSK9

Updated on 15-June-2016

2p4e, 2pmw, 2qtw – hPCSK9 – human

3bps, 2w2m, 3gcx – hPCSK9 + LDLR EGF-A
2w2n, 3gcw – hPCSK9 + LDLR EGF-A (mutant)
2w2o, 2w2p, 2w2q – hPCSK9 (mutant) + LDLR EGF-A
3h42 – hPCSK9 (mutant) + antibody
2xtj, 3sqo, 4k8r – hPCSK9 + antibody
3m0c – hPCSK9 (mutant) + LDLR
3p5b, 3p5c – hPCSK9 + LDLR variant

References

1. ↑ Piper DE, Jackson S, Liu Q, Romanow WG, Shetterly S, Thibault ST, Shan B, Walker NP. The crystal structure of PCSK9: a regulator of plasma LDL-cholesterol. Structure. 2007 May;15(5):545-52. PMID:17502100 doi:http://dx.doi.org/10.1016/j.str.2007.04.004
2. ↑ Seidah NG. Proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors in the treatment of hypercholesterolemia and other pathologies. Curr Pharm Des. 2013;19(17):3161-72. PMID:23317404
3. ↑ Walley KR, Thain KR, Russell JA, Reilly MP, Meyer NJ, Ferguson JF, Christie JD, Nakada TA, Fjell CD, Thair SA, Cirstea MS, Boyd JH. PCSK9 is a critical regulator of the innate immune response and septic shock outcome. Sci Transl Med. 2014 Oct 15;6(258):258ra143. doi: 10.1126/scitranslmed.3008782. PMID:25320235 doi:http://dx.doi.org/10.1126/scitranslmed.3008782