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 tissue was completely phosphorylated in vitro by catalytic subunit of PKA from bovine heart.
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 incorporation confirmed by reaction with monoclonal antibody that doesn't react with phosphorylated cTnI in ELISA and immunoblotting.
Lyophilized from 0.01 M HCl.
It is recommended to reconstitute this product with Tris/urea buffer (20 mM Tris, pH 7.5, 7 M urea, 5 mM EDTA, 15 mM 2-mercaptoethanol) to a concentration close to 1 mg/ml.
Solubility is limited at neutral pH and physiological salt concentration.
Lyophilized -20°C (-15 … -30 °C allowed)
Reconstituted -70°C (-65 … -80 °C allowed)
Avoid repeated freezing and thawing. It is recommended to aliquot the product after reconstitution.
This product is sold for research use only. Standard Laboratory Practices should be followed when handling this material.