Back تروبونين I Arabic Troponina I Spanish Troponina I Galician Troponina I Italian Troponīns I Latvian/Lettish Troponina I Portuguese
| Troponin T | |
|---|---|
| Test of | Troponin |
| LOINC | 14890-5 |
Troponin I is a cardiac and skeletal muscle protein family. It is a part of the troponin protein complex, where it binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. Troponin I prevents myosin from binding to actin in relaxed muscle. When calcium binds to the troponin C, it causes conformational changes which lead to dislocation of troponin I. Afterwards, tropomyosin leaves the binding site for myosin on actin leading to contraction of muscle. The letter I is given due to its inhibitory character. It is a useful marker in the laboratory diagnosis of heart attack.[2] It occurs in different plasma concentration but the same circumstances as troponin T - either test can be performed for confirmation of cardiac muscle damage and laboratories usually offer one test or the other.[3]
Three paralogs with unique tissue-specific expression patterns are expressed in humans, listed below with their locations and OMIM accessions:
- Slow-twitch skeletal muscle isoform troponin I, TNNI1 (1q31.3, 191042)
- Fast-twitch skeletal muscle isoform troponin I, TNNI2 (11p15.5, 191043)
- Cardiac troponin I, TNNI3 (19q13.4, 191044)
- ^ Takeda, Soichi; Yamashita, Atsuko; Maeda, Kayo; Maéda, Yuichiro (July 2003). "Structure of the core domain of human cardiac troponin in the Ca2+-saturated form". Nature. 424 (6944): 35–41. Bibcode:2003Natur.424...35T. doi:10.1038/nature01780. ISSN 1476-4687. PMID 12840750. S2CID 2174019.
- ^ "Troponin". labtestsonline. 27 January 2021.
- ^ "Troponin". labtestsonline.org/. 2019-01-09. Retrieved 2019-07-16.