TNNI3 Human

Troponin I (TNNI3) is the inhibitory subunit of the troponin complex. It binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place, preventing myosin from binding to actin in relaxed muscle . This inhibition is crucial for the regulation of muscle contraction and relaxation. When calcium ions bind to troponin C, a conformational change occurs, allowing myosin to interact with actin and initiate muscle contraction .

Cardiac Troponin I is highly specific to cardiac tissue and is released into the bloodstream when myocardial injury occurs. This makes it an essential biomarker for diagnosing acute myocardial infarction (AMI) and other forms of myocardial damage . The clinical measurement of serum cTnI has become a standard tool in the diagnosis of AMI .

Recombinant human cardiac troponin I is produced using recombinant DNA technology, typically expressed in Escherichia coli (E. coli) cells . This method allows for the production of high-purity cTnI, which is essential for research and clinical applications. The recombinant protein is often lyophilized and can be reconstituted for use in various assays .

The variability in clinical cTnI assay results has led to the development of certified reference materials to standardize these measurements. The National Institute of Standards and Technology (NIST), in collaboration with the AACC/IFCC Cardiac Troponin I Standardization Committee, has developed a certified reference material (SRM 2921) for human cardiac troponin I . This reference material provides traceability to the International System of Units (SI) and aims to harmonize cTnI assays globally .

Recombinant human cardiac troponin I is used in various applications, including:

• Clinical Diagnostics: As a biomarker for myocardial injury.
• Research: Studying the mechanisms of muscle contraction and regulation.
• Drug Development: Screening potential cardiotoxic effects of new drugs.