Tetsu Narumi

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GPGPU (General-purpose computing on graphics processing units) has several difficulties when used in cloud environment, such as narrow bandwidth, higher cost, and lower security, compared with computation using only CPUs. Most high performance computing applications require huge communication between nodes, and do not fit a cloud environment, since network(More)
We are developing the 'Protein Explorer' system, a petaflops special-purpose computer system for molecular dynamics simulations. The Protein Explorer is a PC cluster equipped with special-purpose engines that calculate nonbonded interactions between atoms, which is the most time-consuming part of the simulations. A dedicated LSI 'MDGRAPE-3 chip' performs(More)
As an entry for the 2009 Gordon Bell price/performance prize, we present the results of two different hierarchical <i>N</i>-body simulations on a cluster of 256 graphics processing units (GPUs). Unlike many previous <i>N</i>-body simulations on GPUs that scale as <i>O</i>(<i>N</i><sup>2</sup>), the present method calculates the <i>O</i>(<i>N</i> log(More)
We have achieved a sustained performance of 55 TFLOPS for molecular dynamics simulations of the amyloid fibril formation of peptides from the yeast Sup35 in an aqueous solution. For performing the calculations, we used the MDGRAPE-3 system---a special-purpose computer system for molecular dynamics simulations. Its nominal peak performance was 415 TFLOPS for(More)
Virtual compound screening using molecular docking is widely used in the discovery of new lead compounds for drug design. However, this method is not completely reliable and therefore unsatisfactory. In this study, we used massive molecular dynamics simulations of protein-ligand conformations obtained by molecular docking in order to improve the enrichment(More)
Ligand-activated and tyrosine-phosphorylated ErbB3 receptor binds to the SH2 domain of the p85 subunit of phosphatidylinositol 3-kinase and initiates intracellular signaling. Here, we studied the interactions between the N- (N-SH2) and C- (C-SH2) terminal SH2 domains of the p85 subunit of the phosphatidylinositol 3-kinase and eight ErbB3 receptor-derived(More)
We studied the interactions between the SH2 domain of growth factor receptor binding protein 2 (Grb2) and ErbB receptor-derived phosphotyrosyl peptides using molecular dynamics, free energy calculations, and surface plasmon resonance (SPR) analysis. Binding free energies for nine phosphotyrosyl peptides were calculated using the MM-PBSA continuum solvent(More)
RNA polymerase (Pol) II is a fundamental and important enzyme in the transcription process. However, two mysterious questions have remained unsolved: how an unwound bubble of DNA is established and maintained, and how the enzyme moves along the DNA. To answer these questions, we constructed a model structure of the Pol II elongation complex with the 50 base(More)
Activated receptor tyrosine kinases bind the Shc adaptor protein through its N-terminal phosphotyrosine-binding (PTB) and C-terminal Src homology 2 (SH2) domains. After binding, Shc is phosphorylated within the central collagen-homology (CH) linker region on Tyr-317, a residue remote to both the PTB and SH2 domains. Shc phosphorylation plays a pivotal role(More)