Geisler N, Kaufmann E, Weber K
Cell. 1982 Aug;30(1):277-86. doi: 10.1016/0092-8674(82)90033-2.
Limited chymotryptic cleavage of soluble chicken gizzard desmin protofilaments allows the characterization of three structurally distinct domains. A surface-exposed very basic amino-terminal region (the headpiece) with an amino acid sequence excluding alpha-helical organization (7.5 kd) is separated from the perhaps globular carboxy-terminal 48 residues (the tailpiece) by a distinctly different middle domain of approximately 330 residues. This 38 kd domain is very rich in alpha-helix (at least 83%), and electron microscopy reveals a thin rod with a length of 500 +/- 50 A. Amino acid sequence data also show that the rod domain is interrupted by a nonhelical portion. An alpha-helical array is able to form a coiled-coil spanning the carboxy-terminal half of the 38 kd domain. The alpha-type diffraction pattern of 10 nm filaments arises from a coiled-coil conformation displayed through most but not all of the middle domain of the protofilaments.
对可溶性鸡砂囊结蛋白原纤维进行有限的胰凝乳蛋白酶切割，可对三个结构不同的结构域进行表征。一个表面暴露的非常碱性的氨基末端区域（头部），其氨基酸序列不包括α-螺旋结构（7.5kd），与可能呈球状的羧基末端48个残基（尾部）被一个明显不同的中间结构域隔开，该中间结构域约有330个残基。这个38kd的结构域富含α-螺旋（至少83%），电子显微镜显示为一根长度为500±50埃的细杆。氨基酸序列数据还表明，杆状结构域被一个非螺旋部分打断。一个α-螺旋阵列能够形成一个卷曲螺旋，跨越38kd结构域的羧基末端一半。10nm细丝的α型衍射图案源于原纤维中间结构域大部分但不是全部所呈现的卷曲螺旋构象。
