Characterization and preliminary crystallographic data on the VL-related fragment of the human kI Bence Jones protein Wat.
Characterization and preliminary crystallographic data on the VL-related fragment of the human kI Bence Jones protein Wat.
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人类 kI Bence Jones 蛋白 Wat VL 相关片段的表征和初步晶体学数据。
DOI：
10.1016/0022-2836(81)90086-3
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发表时间：
1981
影响因子：
5.6
通讯作者：
Solomon,A
中科院分区：
文献类型：
--
作者：
Stevens,FJ;Westholm,FA;Panagiotopoulos,N;Schiffer,M;Popp,RA;Solomon,A
一种“天然存在的”人κI V L二聚体，命名为Wat，已被分离和结晶。蛋白质Wat由两个非共价结合的单体组成，每个单体的分子量约为11，500。单体亚基由整个可变区轻链（VL）结构域组成，与κI Bence Jones蛋白Roy（Hilschmann &克雷格，1965）的结构域高度同源，如氨基酸组成、胰蛋白酶肽图谱和序列分析所证实。免疫化学研究证实Wat蛋白属于κ链亚组κI，缺乏与κ恒定区轻链结构域相关的同种型和同种异型抗原决定簇。从硫酸铵或聚乙二醇溶液中得到两种类型的V L二聚体Wat晶体。I型晶体的晶胞尺寸为a= B= 82.6 A/cm，c= 60.3 A/cm，空间群为六方P6 2或P6 4。不对称单元由一个V L二聚体组成;溶剂占据的晶胞体积分数为0.51。Ⅱ型晶体的晶胞尺寸为a= B= 108.3 A/cm，c= 108.8 A/cm，空间群为六方P6 1 22或P6 5 22。三个可变域构成II型晶体的不对称单元;溶剂的分数值（0.52）与I型晶体获得的值相容。
A “naturally occurring” human κI V L dimer, designated Wat, has been isolated and crystallized. Protein Wat consists of two non-covalently bound monomers, each having a molecular weight of~ 11,500. The monomer subunit is composed of an entire variable region light chain (V L) domain closely homologous to that of the κI Bence Jones protein Roy (Hilschmann & Craig, 1965) as evidenced from amino acid composition, tryptic peptide map, and sequence analysis. Immunochemical studies substantiated that protein Wat is of the κ chain subgroup κI and lacks the isotypic and allotypic antigenic determinants associated with the κ constant region light chain domain. Two types of crystals of V L dimer Wat were obtained from ammonium sulfate or polyethylene glycol solutions. The type I crystals have unit cell dimensions of a= b= 82.6 A ̊, c= 60.3 A ̊, and the space group is hexagonal P6 2 or P6 4. The asymmetric unit consists of one V L dimer; the fractional volume of unit cell occupied by solvent is 0.51. The unit cell dimensions of the type II crystals are a= b= 1, 08.3 A ̊, c= 108.8 A ̊; the space group is hexagonal P6 1 22 or P6 5 22. Three variable domains constitute the asymmetric unit of the type II crystals; the fractional value of the solvent (0.52) is compatible with the value obtained for the type I crystals.