Titin: Quantitative mass measurements by scanning transmission electron microscopy and structural implications for the sarcomere matrix of skeletal muscle

FEBS Letters

Hainfeld, James F.¹  Wall, Joseph S.¹  Wang, Kuan² 

[1] Department of Biology, Brookhaven National Laboratory, Upton, NY 11973 USA;Clayton Foundation Biochemical Institute, Department of Chemistry and Cell Research Institute, University of Texas at Austin, TX 78712, USA

关键词: Titin;    Connectin;    Scanning transmission EM;    Sarcomere matrix;    Elastic filament;    (Skeletal muscle);   

DOI  :  10.1016/0014-5793(88)81321-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Scanning transmission electron microscopy has been used to investigate mass and linear mass density of native titin-2, a large soluble fragment of intact titin, from rabbit skeletal muscle. Dark field images of unstained, freeze-dried titin-2 appeared as either compact globules or looser and larger balls of string. Direct mass measurements indicated that the compact forms have an average mass of 2.40±0.50 × 10⁶ Da. The mass to length ratio, determined from well-spread portions of titin strands (3–5 nm wide) from the ball of string forms, averaged 2.7±0.9 kDa/nm. Thus a single native intact titin molecule has a calculated contour length of well above ∼1 μm, sufficient to span unidirectionally between the Z line and M line region in a resting-length sarcomere.

【 授权许可】

Unknown