Analysis of the stabilization of hen lysozyme by helix macrodipole and charged side chain interaction.
Analysis of the stabilization of hen lysozyme by helix macrodipole and charged side chain interaction.
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通过螺旋巨偶极和带电侧链相互作用分析母鸡溶菌酶的稳定性。
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
T. Imoto
中科院分区：
文献类型：
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作者：
H. Motoshima;S. Mine;K. Masumoto;Y. Abe;H. Iwashita;Y. Hashimoto;Y. Chijiiwa;T. Ueda;T. Imoto
在c型溶菌酶α -螺旋的n端区域，两个Asx残基分别位于第18位和第27位。该溶菌酶具有Asp18/Asn27 (18D/27N)，制备了Asn18/Asn27 （18N/27N）、Asn18/Asp27 （18N/27D）和Asp18/Asp27 （18D/27D）三种溶菌酶突变体。野生型（18D/27N）溶菌酶的稳定性支持Asp18侧链与α -螺旋N1位酰胺基团之间存在氢键，而18N/27D溶菌酶的稳定性支持Ser24 （N-cap）与Asp27残基之间存在盖层盒。虽然在18D/27D溶菌酶中Asp18和Asp27残基之间存在静电斥力，但每个残基的解离通过氢键和电荷-螺旋大偶极子相互作用稳定了18D/27D溶菌酶的b螺旋结构。这是第一个证明在螺旋的n端两个相邻的负电荷都增加了蛋白质的稳定性的证据。
In the N-terminal region of the alpha-helix of the c-type lysozymes, two Asx residues exist at the 18th and 27th positions. Hen lysozyme has Asp18/Asn27 (18D/27N), and we prepared three mutant lysozymes, Asn18/Asn27 (18N/27N), Asn18/Asp27 (18N/27D), and Asp18/Asp27 (18D/27D). The stability of the wild-type (18D/27N) lysozyme supported the existence of a hydrogen bond between the side chain of Asp18 and the amide group at the N1 position in the alpha-helix, while the stability of the 18N/27D lysozyme supported the presence of the capping box between the Ser24 (N-cap) and Asp27 residues. Although electrostatic repulsion was observed between Asp18 and Asp27 residues in 18D/27D lysozyme, the dissociation of each residue contributed to stabilizing the B-helix in 18D/27D lysozyme through hydrogen bonding and charge-helix macrodipole interaction. This is the first evidence that two neighboring negative charges at the N-terminus of the helix both increased the stability of the protein.