Time-resolved detection of sensory rhodopsin II-transducer interaction
Time-resolved detection of sensory rhodopsin II-transducer interaction
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DOI：
10.1529/biophysj.104.043521
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发表时间：
2004-10-01
影响因子：
3.4
通讯作者：
Terazima, M
中科院分区：
文献类型：
--
作者：
Inoue, K;Sasaki, J;Terazima, M
用激光研究了法老钠杆菌（Natronobacterium pharaonis）感视紫红质II （NpSRII）和NpSRII与同源换能器（NpHtrII）在n端截断159个氨基酸序列（NpSRII- deltanphtrii）的构象变化动力学。实时灰光解和瞬态光栅方法。两种物质的扩散系数表明，NpSRII-DeltaNpHtrII在0.6%十二烷基- β -麦芽吡喃苷（DM）溶液中以二聚体形式存在。用瞬态吸收法和光栅法测定的光循环反应过程速率常数吻合较好。NpSRII和NpSRII- deltanphtrii样品的体积变化和分子能存在显著差异。与NpSRII相比，NpSRII- deltanphtrii的第二中间体焓(L)更稳定。这种稳定性表明，在早期中间物种中，传感器通过络合物的形成对NpSRII结构产生了影响。NpSRII在最后两个步骤中有较大的分子体积膨胀和收缩。DeltaNpHtrII的存在诱导了额外的体积膨胀和收缩。这种体积变化应该反映了换能器蛋白诱导的构象变化，提示这是NpSRII-DeltaNpHtrII的信号转导过程。
The dynamics of protein conformational change of Natronobacterium pharaonis sensory rhodopsin II (NpSRII) and of NpSRII fused to cognate transducer (NpHtrII) truncated at 159 amino acid sequence from the N-terminus (NpSRII-DeltaNpHtrII) are investigated in solution phase at room temperature by the laser. ash photolysis and the transient grating methods in real time. The diffusion coefficients of both species indicate that the NpSRII-DeltaNpHtrII exists in the dimeric form in 0.6% dodecyl-beta-maltopyranoside (DM) solution. Rate constants of the reaction processes in the photocycles determined by the transient absorption and grating methods agree quite well. Significant differences were found in the volume change and the molecular energy between NpSRII and NpSRII-DeltaNpHtrII samples. The enthalpy of the second intermediate (L) of NpSRII-DeltaNpHtrII is more stabilized compared with that of NpSRII. This stabilization indicates the influence of the transducer to the NpSRII structure in the early intermediate species by the complex formation. Relatively large molecular volume expansion and contraction were observed in the last two steps for NpSRII. Additional volume expansion and contraction were induced by the presence of DeltaNpHtrII. This volume change, which should reflect the conformational change induced by the transducer protein, suggested that this is the signal transduction process of the NpSRII-DeltaNpHtrII.