Foundation for Promotion of Material Science and Technology of Japan

The plasma membrane (PM) serves multiple functions to support cell activities with its heterogeneous molecular distribution. Fatty acids (FAs) are hydrophobic components of the PM whose saturation and length determine the membrane’s physical properties. The FA distribution contributes to the PM’s lateral heterogeneity. However, the distribution of PM FAs is poorly understood. Here, we proposed the FA cluster hypothesis, which suggested that FAs on the PM exist as clusters. By the optogenetic tool translocating the endoplasmic reticulum (ER), we were able to manipulate the distribution of PM FAs. We used time-of-flight combined secondary ion mass spectrometry (TOF-SIMS) to image PM FAs and discovered that PM FAs were presented and distributed as clusters and are also manipulated as clusters. We also found the existence of multi-FA clusters formed by the colocalization of more than one FA. Our optogenetic tool also decreased the clustering degree of FA clusters and the formation probability of multi-FA clusters. This research opens up new avenues and perspectives to study PM heterogeneity from an FA perspective. This research also suggests a possible treatment for diseases caused by PM lipid aggregation and furnished a convenient tool for therapeutic development.

It is important to understand the conformational changes of both the crystalline and the noncrystalline domains of Bombyx mori silk fibroin as they are stretched from soluble Silk I to the mature Silk II fiber, to be able to design man-made strong and tough silk fibers. Here, the Ser, Tyr, and Ala Cβ of silk fibroin were labeled by 13C to obtain domain-specific structural information, because Ser residues are present predominantly in the crystalline domains, Tyr predominantly in the noncrystalline domains and Ala residues in both domains. The conformational change was monitored by 13C CP/MAS NMR using the conformation-dependent 13C NMR chemical shift. With increasing stretching ratio, initially there is a change from Silk I* (a repeated type II β-turn structure) to β-sheet in the longer AGSGAG sequences, followed by shorter AGSGAG sequences, while the noncrystalline domains change gradually from random coil to β-sheet during the whole conformational change.

NAL Numerical Wind Tunnel (NWT) is a distributed memory parallel computer developed through joint research and development of NAL and Fujitsu. It is based on the analysis of CFD codes developed in NAL. The target performance is more than 100 times faster than VP400. In this paper, the parallel computation model employed in the development of the NWT is described. The specification and feature of the NWT and the NWT Fortran are discussed. Finally, performance evaluations and some applications are presented. We find that the target performance is attained.

NAL Numerical Wind Tunnel (NWT) is a distributed memory parallel computer developed through joint research and development of NAL and Fujitsu. It is based on the analysis of CFD codes developed in NAL. The target performance is more than 100 times faster than VP400.In this paper, the parallel computation model employed in the development of the NWT is described. The specification and feature of the NWT and the NWT Fortran are discussed. Finally, Performance evaluations and some applications are presented.We find that the target performance is attained.