Human heart tissue.
Blood samples from the tissue donors were tested and found negative for HBsAg, HIV-1 and HIV-2 antibodies, HCV, and syphilis.
TnI is the inhibitory subunit of troponin, the thin filament regulatory complex which confers calcium sensitivity to striated muscle actomyosin ATPase activity.
Cardiac isoform of TnI (cTnI) has two serine residues at positions 22 and 23 which could be phosphorylated by cAMP-dependent protein kinase (PKA) in response to β-adrenergic stimulation of the heart. Modification of these serines results in the changes of myocardial contractility. About 50% of cTnI purified from human cardiac tissue is mono- or biphosphorylated.
cTnI purified from human cardiac muscle was dephosphorylated in vitro using alkaline phosphatase from E. coli.
TnI is suitable for use as a standard in immunoassay, immunogen for antiserum production.
Purity > 95 %.
TnI concentration was determined spectrophotometrically using A (0.1 %, 280 nm, 1 cm) equal to 0.42. This coefficient was calculated from the amino composition of human cTnI (FEBS Lett, 270, 57-61).
Phosphate group removal confirmed by reaction with monoclonal antibody that doesn't react with phosphorylated cTnI in ELISA and immunoblotting.
Frozen in 60 mM Tris-HCl, pH 7.3, 285 mM NaCl, 6 mM EGTA, 15 mM MgCl2, 3 mM DTT, 150 μM ATP, 1.5 mM CaCl2, 2.3 % glycerol and traces of (NH4)2SO4 and alkaline phosphatase.
-20 °C (-15 … -30 °C allowed)
-70 °C for long term storage (-65 … -80 °C allowed)
Avoid repeated freezing and thawing.
This product is sold for research use only. Standard Laboratory Practices should be followed when handling this material.