Description

Genorise Recombinant Human MyBPC3 Protein Summary

Alternative names for MyBPC3: The myosin-binding protein C, cardiac-type (MyBPC3 or cMyBP-C)

Product Specifications

Background: 

The myosin-binding protein C, cardiac-type (MyBPC3 or cMyBP-C) is a protein that in humans is encoded by the MYBPC3 gene.^[1] This isoform is expressed exclusively in heart muscle during human and mouse development,^[2] and is distinct from those expressed in slow skeletal muscle (MYBPC1) and fast skeletal muscle (MYBPC2). cMyBP-C is a 140.5 kDa protein composed of 1273 amino acids.^[3] cMyBP-C is a myosin-associated protein that binds at 43 nm intervals along the myosin thick filament backbone, stretching for 200 nm on either side of the M-line within the crossbridge-bearing zone (C-region) of the A band in striated muscle. The approximate stoichiometry of cMyBP-C along the thick filament is 1 per 9-10 myosin molecules, or 37 cMyBP-C molecules per thick filament. In addition to myosin, cMyBP-C also binds titin and actin.^[4] The cMyBP-C isoform expressed in cardiac muscle differs from those expressed in slow and fast skeletal muscle (MYBPC1 and MYBPC2, respectively) by three features: (1) an additional immunoglobulin (Ig)-like domain on the N-terminus, (2) a linker region between the second and third Ig domains, and (3) an additional loop in the sixth Ig domain.^[5] cMyBP-C appears necessary for normal order, filament length and lattice spacing within the structure of the sarcomere.^[6] cMyBP-C is not essential for sarcomere formation during embryogenesis, but is crucial for sarcomere organization and maintenance of normal cardiac function. Absence of cMyBP-C results in severe cardiac hypertrophy, increased heart-weight-to-body-weight-ratios, enlargement of ventricles, increased myofilament Ca2+ sensitivity and depressed diastolic and systolic function.^[7] Histologically, MyBPC3-targeted knock-out hearts display structural rearrangements with cardiac myocyte disarray and increased interstitial fibrosis similar to patients with hypertrophic cardiomyopathy, without obvious alterations in shape or size of single cardiac myocytes, a loss of lateral alignment of adjacent myofibrils with their Z-lines misaligned.^[7]

References

1. Gautel M, et al. (1995). The EMBO Journal. 14 (9): 1952–60.
2. Fougerousse F, et al. (1998). Circulation Research. 82 (1): 130–3.
3. Carrier L, et al. (1997). Circulation Research. 80 (3): 427–34.
4. Freiburg A, et al. (1996). European Journal of Biochemistry / FEBS. 235 (1–2): 317–23.
5. Winegrad S (1999). Circulation Research. 84 (10): 1117–26.
6. Colson BA, et al. (2007). Journal of Molecular Biology. 367 (1): 36–41.
7. Harris SP, et al. (2002). Circulation Research. 90 (5): 594–601.