MATURATION INTERMEDIATES OF A T=4 VIRUS CAPSID STUDIED BY TIME-RESOLVED X-RAY SC

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 新月形虫Omega病毒样颗粒是一种T=4病毒衣壳，经历了一个pH促进的成熟过程。使用SSRL BL4-2上的完全升级的仪器，我们已经开始研究与成熟过程相关的结构变化的动力学。通过进行手动混合，然后进行一系列时间分辨数据采集(每次3秒曝光)，我们最近能够在中性(pH 7.6)和pH 5.0之间分离出一种结构中间体，这在我们早期的研究中被用来促进成熟。我们还观察到两个RNA含量不同的VLP的形状和直径略有不同。我们以毫秒的时间分辨率启动了对整个成熟过程的时间分辨研究，试图验证我们的假设，即3倍和准3倍轴上衣壳亚单位之间的排斥静电力是成熟过程中的关键触发事件。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Nudaurelia capensis omega virus-like particle, a T=4 virus capsid, undergoes a pH promoted maturation process. Using the fully upgraded instrumentation on SSRL BL4-2 we have begun studying the kinetics of structural change associated with the maturation process. Performing manual mixing, followed by a series of time-resolved data acquisition (each 3 sec exposure), we have recently been able to isolate a structural intermediate at intermediary pH values between neutral (pH 7.6) and pH 5.0, which was used to promote the maturation in our earlier studies. We also observed that two VLPs with different RNA contents show slightly different shape and diameter. We have initiated the time-resolved studies of the entire process of maturation with a millisecond time-resolution in an attempt to examine our hypothesis that the repulsive electrostatic forces among the capsid subunits at the 3-fold and quasi 3-fold axies being the key triggering event in the maturation.