Calpain-1

Summary

Protein Function

Calpain-1 catalytic subunit is a protein that in humans is encoded by the CAPN1 gene. The calpains, calcium-activated neutral proteases, are nonlysosomal, intracellular cysteine proteases. The mammalian calpains include ubiquitous, stomach-specific, and muscle-specific proteins. The ubiquitous enzymes consist of heterodimers with distinct large, catalytic subunits associated with a common small, regulatory subunit. (From Wikipedia)
Calcium-regulated non-lysosomal thiol-protease which catalyze limited proteolysis of substrates involved in cytoskeletal remodeling and signal transduction. Broad endopeptidase specificity. (From Uniprot)

Cys Function & Property

Cys115 is one of the active sites of Cathepsin H, which is very close to His272 and Asn296 in space. These three residues formed a typical catalytic triad motif.

• Hydrophobic property:

• SASA：

Cys115: 12.816 A^2

Protein Sequence

MAEELITPVY CTGVSAQVQK QRDKELGLGR HENAIKYLGQ DYENLRARCL
QNGVLFQDDA FPPVSHSLGF KELGPNSSKT YGIKWKRPTE LLSNPQFIVD
GATRTDICQG ALGDCWLLAA IASLTLNETI LHRVVPYGQS FQEGYAGIFH
FQLWQFGEWV DVVVDDLLPT KDGKLVFVHS AQGNEFWSAL LEKAYAKVNG
SYEALSGGCT SEAFEDFTGG VTEWYDLQKA PSDLYQIILK ALERGSLLGC
SINISDIRDL EAITFKNLVR GHAYSVTDAK QVTYQGQRVN LIRMRNPWGE
VEWKGPWSDN SYEWNKVDPY EREQLRVKME DGEFWMSFRD FIREFTKLEI
CNLTPDALKS RTLRNWNTTF YEGTWRRGST AGGCRNYPAT FWVNPQFKIR
LEEVDDADDY DSRESGCSFL LALMQKHRRR ERRFGRDMET IGFAVYQVPR
ELAGQPVHLK RDFFLANASR AQSEHFINLR EVSNRIRLPP GEYIVVPSTF
EPNKEGDFLL RFFSEKKAGT QELDDQIQAN LPDEKVLSEE EIDDNFKTLF
SKLAGDDMEI SVKELQTILN RIISKHKDLR TNGFSLESCR SMVNLMDRDG
NGKLGLVEFN ILWNRIRNYL TIFRKFDLDK SGSMSAYEMR MAIEAAGFKL
NKKLHELIIT RYSEPDLAVD FDNFVCCLVR LETMFRFFKI LDTDLDGVVT
FDLFKWLQLT MFA

Structural Information

• Known structures with covalent ligands:
  

1TL9, 1TLO

• Protein structure:

Related Pathway

• Protein processing in endoplasmic reticulum
  
• Apoptosis
  
• Necroptosis
  
• Cellular senescence
  
• Alzheimer disease
  

Experimental Evidence

Crystallography

Reference

1. Moldoveanu T, Campbell R L, Cuerrier D, et al. Crystal structures of calpain–E64 and–leupeptin inhibitor complexes reveal mobile loops gating the active site[J]. Journal of molecular biology, 2004, 343(5): 1313-1326. 15491615