Human cardiac troponin I (cTnI)

Human heart tissue.
Blood sample from the tissue donors was tested and found negative for HBsAg, HIV-1 and HIV-2 antibodies, HCV, and syphilis.

Immunological and biochemical studies.TnI is the inhibitory subunit of troponin, the thin filament regulatory complex which confers calcium sensitivity to striated muscle actomyosin ATPase activity.

TnI exists in three isoforms, one for slow-twitch skeletal muscle, one for fast twitch skeletal muscle and one for cardiac muscle. The amino acid sequences of two skeletal (skTnI) and one cTnI forms show 40% dissimilarity. Furthermore, the human cTnI has additional amino acid residues on its Nterminal region that are not present on the skeletal form, making this protein a promising analyte for indicating cardiac specificity. cTnI follows similar release pattern as CK-MB within the first 15 hours of myocardial infarction (MI), but remains elevated in serum up to 6 days. This observation and the unique amino sequence of cTnI make it an important diagnostic marker of MI.

TnI is suitable for use as a standard in immunoassay for early detection of MI, immunogen for
antiserum production and tracer for iodination.

Purity > 98 % (SDS-PAGE).
Immunological activity confirmed by reaction with monoclonal antibody that is specific for the troponin I cardiac isoform in immunoblotting.
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).

Lyophilized from 0.01 M HCl.
Product is recommended to reconstitute with urea/Tris buffer, pH 7.5 (7 M urea, 5 mM EDTA, 15 mM mercapthoethanol, 20 mM Tris) to concentration around 1mg/ml.
Solubility is limited at neutral pH and physiological salt concentration.

-20 °C (between -15 and -30 °C allowed)
-70 ºC for long term storage (between -65 and -80 °C allowed)

This product is sold for research use only. Standard Laboratory Practices should be followed when handling this material.

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