イマムラ ヒロシ
今村 比呂志
IMAMURA HIROSHI
所属 生命科学部 応用化学科
職名 助教
言語種別 英語
研究概要 Folding and aggregation of natural and artificial proteins

My major is biophysics including physical chemistry and protein science. I have been interested in (re)design and characterization of natural and artificial proteins (For example, doi:10.1021/bi2019223). It provides an insight to how proteins gain the incredible characters including self-organization, selective high/low solubility, and various functions via molecular evolution.
Recently, I have worked on extracting intermolecular interaction governing protein’s self-assemblies such as aggregation, solubility, crystallization, or functional association of proteins, by using scattering and spectroscopic techniques. For example, the recent paper (doi: 10.1039/c4cp03606a) demonstrated that a modified liquid state theory allowed us to determine the intermolecular potential of lysozyme without presuming any function of model potentials.
Increasing use of proteins for therapy requests strict regulation of protein folding and aggregation. The paper (doi: 10.1021/acs.jpcb.6b05473) focused on acid treatment in the purification process of an antibody drug, which induces its unfolding and aggregation. Static and dynamic light scattering revealed that the antibody formed fractal aggregates, the growth kinetics of which is well described by Smoluchowski aggregation equation; intermolecular interaction controlling the aggregation was quantified. This model would be useful for improving manufacturing processes of antibodies.
Previously, I worked on pressure effect on conformational stabilities of model proteins/peptides, to address the mechanism of pressure denaturation of proteins, which have long been an open issue in the fields of biophysics and solution chemistry. The papers (e.g., doi:10.1002/prot.22302) highlight an important point that pressure promotes the formation of the α-helices of synthetic model peptides, which seems quite different from pressure denaturation of proteins. The underlying mechanism has also been proposed. High-pressure FTIR spectroscopic technique played a key role to resolve the mystery of the relationship between polypeptide’s chirality and their structure (doi: 10.1021/jp2125685).