Since biological molecular machines such as molecular motors, cell signal processors, DNA transcription processors and protein synthesizers are only nanometers in size and have a flexible structure, they are very prone to thermal agitation. Furthermore, the input energy level is not much different from that of average thermal energy, kBT. Molecular machines can use this thermal noise with a high efficiency of energy conversion for their functions. This is in sharp contrast to man-made machines that operate at energies much higher than thermal noise. In recent years, single molecule imaging and nano-technologies have rapidly been expanding to include a wide range of life science applications. The dynamic properties of biomolecules and the unique operations of molecular machines, which were previously hidden in averaged ensemble measurements, are now being unveiled. The aim of our research is to approach the engineering principle of adaptive biological systems by uncovering the unique operation of biological molecular machines. Here, I review our single molecule experiments designed to investigate molecular motors, enzyme reactions, protein dynamics and cell signaling, and discuss how thermal fluctuations (noise) play a positive role in the unique operation of biological molecular machines allowing for flexible and adaptive biological systems including cell and brain.
Toshio Yanagida was born in Hyogo prefecture in 1946. He graduated from Osaka University and received the Doctor of Engineering degree in 1976. He was a Professor at Osaka University’s Graduate School of Information Science and Technology from 1988, Department of Physiology and Biosignaling, Graduate School of Medicine from 1996, and the Graduate School of Frontier Biosciences from 2002. His research was grounded by the development of pioneering new single-molecule detection techniques, which allowed him to make fundamental discoveries on the molecular mechanisms of muscle contraction, and the role of fluctuation in the function of biomolecular machine. In his later research, he has extended the core idea of fluctuation mechanisms from molecular motors to cells and brain.
He worked as the leader of the Yanagida Biomotron Project, ERATO, JST from 1992 to 1997 and its successor, the Single-Molecule Process Project, ICORP, JST from 1998 to 2002. Following these projects, he was Research Director of Soft Nano Machines and Research Supervisor of Novel Measuring and Analytical Technology Contributions to the Elucidation and Application of Life Phenomena, CREST, JST from 2004 to 2012. From 2004 to 2006, he was Vice-Chair of the Council of Scientists of The International Human Frontier Science Program Organization, and from 2006 to 2010, he served as a Member of Council of the Biophysical Society.
More recently, he has served as Director of the RIKEN Quantitative Biology Center (QBiC), and is currently Director of the Center for Information and Neural Networks (CiNet), NICT, while also holding the titles of Specially Appointed Professor, Osaka University, and Director, NEC Brain-Inspired Computing Research Alliance Laboratories. He has received a number of prestigious awards including the Imperial Prize and Japan Academy Prize in 1998, the US Genomic Award for Outstanding Investigator in the Field of Single-Molecule Fluorescence Microscopy in 2010, and Fellow of the US Biophysical Society 2011. He was also honored as a Person of Cultural merit by the Emperor of Japan in 2013.