权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

MOLECULAR AGGREGATION AND INDUCED NUCLEATION IN PROTEIN CRYSTAL GROWTH

蛋白质晶体生长中的分子聚集和诱导成核

基本信息

批准号：
07454068
负责人：
SATO Kiyotaka
金额：
$ 0.51万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454068/
关键词：
PROTEIN CRYSTAL GROWTH MOLECULAR AGGREGATION DYNAMIC LIGHT SCATTERING 動的先錯乱

项目摘要

This research project aimed at analyzing kinetic mechanisms in induced nucleation during the processes of protein crystal growth, mainly using dynamic light scattering techniques and crossed Nicols method. The protein molecules dealt with in the present work were lysozyme and taka-amylase.The results obtained for lysozyme crystallization using the crusaded-Nicols method are summarized in the following ; (1) the induction times were obtained by measuring the duration for the occurrence of crystals in varying supersaturating values, (2) interface energies (gamma) were evaluated from the calculation of the induction times, whose inverse values are proportional to the rates of nucleation, and supersaturation, (3) the gamma values (erg/cm^2) were 0.3 both for sitting and hanging drop methods for crystallization, (4) micro-seeding effects were found to be dependent on the sizes of seed crystals and supersaturations.The results obtained for taka-amylase crystallization are summarized in the following ; (1) diffusion constants and average particle sizes increased quite abruptly after certain induction times in supersaturated solution, (2) the occurrence of this cahnges was prompted with increasing supersaturation values, and followed by the appearance of crystals detectable by naked eyes. Therefore, one may concluded that the molecular clustering of taka-amylase was formed in prior to nucleation, as detected by the dynamic light scattering technique.These results available for the two types of proteins have shown that the pre-nucleation events are detectable, in case that the molecular weights are as large as in taka-amylase. However, more precise experiments are not possible, because the fundamental data of solubility are lacking. Thus, the solubility of taka-amylase is now measured by using a two-beam interferometric method.

本研究主要利用动态光散射技术和正交尼科尔斯方法分析蛋白质晶体生长过程中诱导成核的动力学机制。本文所研究的蛋白质分子是溶菌酶和塔卡淀粉酶。用十字交叉尼科尔斯法结晶溶菌酶的结果总结如下：（1）通过测量在不同的过饱和值下出现晶体的持续时间来获得诱导时间，（2）通过计算诱导时间来评估界面能（γ），其倒数值与成核速率和过饱和速率成正比;（3）γ值（erg/cm ^2）对于用于结晶的坐滴法和悬滴法均为0.3，（4）微晶种效应与晶种的大小和过饱和度有关。淀粉酶结晶的研究概述如下;（1）在过饱和溶液中，扩散常数和平均粒径在一定的诱导时间后急剧增加，（2）随着过饱和度的增加，随后出现肉眼可检测到的晶体。因此，可以得出结论，如动态光散射技术所检测到的，Taka-amylase的分子聚集在成核之前形成。这些可用于两种类型蛋白质的结果表明，在分子量与Taka-amylase一样大的情况下，可检测到预成核事件。然而，更精确的实验是不可能的，因为缺乏溶解度的基本数据。因此，现在通过使用双光束干涉法测量Taka-淀粉酶的溶解度。