Amyloid fibril formation by proteins is one of the important issues in biophysics. The kinetics can be monitored by conventional techniques, such as thioflavin T fluorescence, in vitro. However, the interpretation of such data is not straightforward. Analysis by curve-fitting to stretched exponential was shown to be useful in characterising this complex reaction. Observation of fibril extention under evanescent fluorescence microscope reveals that rates of extention of individual fibrils can vary. The fact that amyloid fibrils are similar to organogels suggests the possibility that the ability of proteins to form amyloids can be utilized to create well-ordered nanostructured materials.
Development of high-throughput methods for protein production is one of the most urgent issues to be addressed in the post-genome era. Recently we have succeeded in constructing a novel translation system, reconstituted in vitro from purified protein components involved in translation, called the PURE system. The PURE system is capable of synthesizing submilligram amount of protein per hour. The protein products are easily purified within one hour by the removal of the tagged translation factors using affinity chromatography. The PURE system will provide the possibility of efficient production of labile products.
The conventional electrophysiological method revealed some aspects of neural network for animal behavior. But it was inappropriate for recording activities of many neurons simultaneously. For the purpose of the multi-cell recording from Aplysia central nervous system, we used the calcium imaging method. Spike activities could be recorded from-30 neurons simultaneously. We also demonstrated that the firing properties of individual neurons, such as frequency or period, and the phase-locked firing patterns of these neurons could be easily detected. Moreover, combining this method with the electrophysiological method, we could identify several motor neurons concerned with the feeding behavior of this animal.