Thermally induced chain exchange of smooth muscle tropomyosin dimers studied by differential scanning calorimetry

FEBS Letters

Gusev, Nikolai B.²  Drachev, Vladimir A.³  Orlov, Victor N.³  Nikolaeva, Olga P.³  Rostkova, Elena V.¹  Levitsky, Dmitrii I.³ 

[1] A.N. Back Institute of Biochemistry, Russian Academy of Sciences, Moscow 117071, Russia;Department of Biochemistry, School of Biology, Moscow State University, Moscow 119899, Russia;A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia

关键词: Tropomyosin;    Coiled-coil dimer;    Thermal unfolding;    Differential scanning calorimetry;    TM;    tropomyosin;    DSC;    differential scanning calorimetry;   

DOI  :  10.1016/S0014-5793(98)00923-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The thermal unfolding of duck gizzard tropomyosin dimers, αβ, αα, and ββ, and of a 1:1 mixture of αα and ββ homodimers was studied by differential scanning calorimetry (DSC). Both αα and ββ homodimers demonstrated a broad thermal transition with maxima at 37.4°C and 44.6°C, respectively. However, a sharp cooperative thermal transition at 41.5°C characteristic for αβ heterodimer appeared on the thermogram of the mixture of homodimers. The appearance of this transition was prevented by disulfide cross-linking of polypeptide chains in the homodimers. Thus, DSC studies clearly demonstrate formation of tropomyosin heterodimers during heating of the mixture of homodimers and in agreement with earlier published reports indicate thermally induced chain exchange between tropomyosin dimers.

【 授权许可】

Unknown