Hydrodynamics, size, and shape of bacteriophage T4D tails and baseplates.
Hydrodynamics, size, and shape of bacteriophage T4D tails and baseplates.
复制标题
噬菌体 T4D 尾部和底板的流体动力学、尺寸和形状。
DOI：
10.1002/bip.360210406
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发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Bloomfield,VA
中科院分区：
文献类型：
--
作者：
Benbasat,JA;Bloomfield,VA
我们已经使用平移扩散系数测量和亚基流体动力学理论来确定噬菌体T4 D基板和尾部的尺寸和形状。Wagenknecht和布卢姆菲尔德先前通过准弹性激光散射（QLS）测定了基板的扩散系数，即D = 8.56 × 10− 8 cm 2/s。用QLS法测得尾部的D = 5.88 × 10− 8 cm 2/s，用Svedberg方程结合沉降系数和分子量计算D = 6.02 × 10− 8 cm 2/s。这些值的不确定性为± 2.7%，当与亚基流体动力学理论相结合时，使我们能够改进通过电子显微镜获得的尺寸估计。对于六边形基板，顶点到顶点的距离约为480 μ m，厚度为160 μ m，并且有六根延伸的短纤维，长度为320 μ m，直径为40 μ m。当这些尺寸的基板连接到1050 <$m长、240 <$m直径的尾管-鞘管-连接器复合体时，计算的D为5.93 × 10− 8 cm 2/s，在实验的1%范围内。这种结合使用电子显微镜和流体力学，使用前者来确定形状，后者来获得溶液尺寸，是一种强有力的方法来研究生物分子复合物的结构。
We have used translational diffusion coefficient measurements and subunit hydrodynamic theory to determine the dimensions and shape of bacterioophage T4D baseplates and tails. The diffusion coefficient of the baseplate, measured by quasielastic laser light scattering (QLS), was determined previously by Wagenknecht and Bloomfield to beD= 8.56 × 10−8cm2/s. For the tail, we foundD= 5.88 × 10−8cm2/s by QLS, andD= 6.02 × 10−8cm2/s by combining sedimentation coefficient and molecular weight in the Svedberg equation. These values, which have an uncertainty of ±2.7%, when combined with subunit hydrodynamic theory, enabled us to refine estimates of dimensions obtained by electron microscopy. For the hexagonal baseplate, the vertex‐to‐vertex distance is about 480 Å, the thickness is 160 Å, and there are six extended short fibers 320‐Å long and 40 Å in diameter. When a baseplate of these dimensions is attached to a tail tube‐sheath‐connector complex 1050‐Å long and 240 Å in diameter, the calculatedDis 5.93 × 10−8cm2/s, within 1% of experiment. This combined use of electron microscopy and hydrodynamics, using the former to ascertain shape, and the latter to obtain solution dimensions, is a powerful approach to the structure of biomolecular complexes.