Skip to Content
Merck
All Photos(1)

Documents

208712

Sigma-Aldrich

Calpain-1, Porcine Erythrocytes

Calpain-1, Porcine Erythrocytes, is a native calpain-1. A heterodimeric cysteine proteinase with low Ca2+ requirement (EC₅₀ = 2 µM).

Synonym(s):

μ-Calpain

Sign Into View Organizational & Contract Pricing


About This Item

Enzyme Commission number:
UNSPSC Code:
12352202
NACRES:
NA.42

Quality Level

form

liquid

specific activity

≥1000 units/mg protein

manufacturer/tradename

Calbiochem®

storage condition

OK to freeze
avoid repeated freeze/thaw cycles

pI 

5.3

shipped in

wet ice

storage temp.

−70°C

Related Categories

General description

Native calpain-1 from porcine erythrocytes. Ca2+-dependent heterodimeric cysteine proteinase with low Ca2+ requirement (EC50= 2 µM). Participates in the ATP release reaction of platelets stimulated with thrombin.
Native calpain-1 from porcine erythrocytes. Calpains are a family of calcium-dependent thiol-proteases that degrade a wide variety of cytoskeletal, membrane-associated, and regulatory proteins. The two major isoforms, calpain I (µ-form) and calpain II (m-form), differ in their calcium requirement for activation. Calpain I requires only micromolar amounts of calcium (EC50 = 2 µM), while calpain II requires millimolar amounts (EC50 = 1 mM).



Calpains are heterodimers of 80 kDa and 30 kDa subunits. The 80 kDa unit has the catalytic site and is unique to each isozyme. The 30 kDa unit is a regulatory subunit and common to both calpain I and calpain II. The 80 kDa unit consists of four domains (I-IV). The 30 kDa unit has two domains (V and VI).



• Domain I is partially removed during autolysis.

• Domain II is the protease domain.

• Domain III exhibits a homology with typical calmodulin binding proteins and interacts with calcium binding domains (IV and VI) and frees domain II for protease activity.

• Domain IV is a calcium binding domain.

• Domain V contains a hydrophobic region and is essential for calpain interaction with membranes.

• Domain VI is a calcium binding domain.



More recently, attention has been focused on the pathological significance of calcium accumulation in the central nervous system following cerebral ischemia and traumatic brain injury. Over-activation of NMDA, kainate, and AMPA receptors in the brain leads to sustained influx in Ca2+ through voltage gated Ca2+ channels. Disturbances in calcium homeostasis result in the activation of several calcium-dependent enzymes including calpains. Over-expression of calpains has been positively linked to both acute and chronic neurodegenerative processes including ischemia, trauma, and Alzheimer′s disease. In Alzheimer′s disease the ratio of active (76 kDa) to inactive (80 kDa) calpain I is reported to be much higher. Calpain proteolysis is usually the late-stage common pathway towards cell death induced by excitotoxic compounds.

Packaging

Please refer to vial label for lot-specific concentration.

Warning

Toxicity: Harmful (C)

Unit Definition

One unit is defined as the amount of enzyme that will hydrolyze 1 pmol Suc-LLVY-AMC in 1 min at 25°C using the Calpain Activity Assay Kit, Fluorogenic (Cat. No. QIA120). Note: 1 caseinolytic unit = 9 fluorogenic units

Physical form

In 20 mM imidazole-HCl, 5 mM β-mercaptoethanol, 1 mM EDTA, 1 mM EGTA, 30% glycerol, pH 6.8.

Reconstitution

Following initial thaw, aliquot and freeze (-70°C). Short-term storage of aliquots at 4°C or on ice is not recommended.

Other Notes

Vanderklish, P.W., and Bahr, B.A. 2000. Int. J. Exp. Pathol.81, 323.
Sorimachi, H., et al. 1997. Biochem. J.328, 721.
Kampfl, A., et al. 1997. J. Neurotrauma14, 121.
Johnson, G.V.W., and Gutmann, R.P. 1997. BioEssays19, 1011.
Bartus, R.T., et al. 1995. Neurol. Res.17, 249.
Wang, K.K.W., and Yuen, P.-W. 1994. Trends Pharmacol. Sci. 15, 412.
Saito, K., et al. 1993. Proc. Natl. Acad. Sci. USA90, 2628.
Goll, D.E., et al. 1992. BioEssays14, 549.
Ishii, H., et al. 1992. Biochim. Biophys. Acta1175, 37.
Melloni, E., and Pontremoli, S. 1989. Trends Neurosci.12, 438.
Ross, E., and Schatz, G. 1973. Anal. Biochem.54, 304.

Legal Information

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

Storage Class Code

10 - Combustible liquids

WGK

WGK 2


Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library

Silke Nuber et al.
Acta neuropathologica, 127(4), 477-494 (2014-02-11)
The olfactory bulb (OB) is one of the first brain regions in Parkinson's disease (PD) to contain alpha-synuclein (α-syn) inclusions, possibly associated with nonmotor symptoms. Mechanisms underlying olfactory synucleinopathy, its contribution to progressive aggregation pathology and nigrostriatal dopaminergic loss observed
Petter Vejle Andersen et al.
Meat science, 139, 239-246 (2018-02-24)
Degree of post-mortem proteolysis influences overall meat quality (e.g. tenderness and water holding capacity). Degradation of isolated pork myofibril proteins by μ-Calpain for 0, 15 or 45 min was analyzed using four spectroscopic techniques; Raman, Fourier transform infrared (FT-IR), near infrared
Anupama Lakshmanan et al.
Nature chemical biology, 16(9), 988-996 (2020-07-15)
Visualizing biomolecular and cellular processes inside intact living organisms is a major goal of chemical biology. However, existing molecular biosensors, based primarily on fluorescent emission, have limited utility in this context due to the scattering of light by tissue. In
Rocco Adiutori et al.
Brain communications, 3(3), fcab148-fcab148 (2021-08-17)
Plasma proteome composition reflects the inflammatory and metabolic state of the organism and can be predictive of system-level and organ-specific pathologies. Circulating protein aggregates are enriched with neurofilament heavy chain-axonal proteins involved in brain aggregate formation and recently identified as
Fumiko Shinkai-Ouchi et al.
Bioscience reports, 40(11) (2020-10-21)
Calpain-1 and calpain-2 are highly structurally similar isoforms of calpain. The calpains, a family of intracellular cysteine proteases, cleave their substrates at specific sites, thus modifying their properties such as function or activity. These isoforms have long been considered to

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service