Protein crystallization method in gel capsules with nucleants for contactless handling of crystals

2015 Fiscal Year Final Research Report

• Project/Area Number: 25650026
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Structural biochemistry
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Sugahara Michihiro 国立研究開発法人理化学研究所, 放射光科学総合研究センター, 特別研究員 (00415192)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: タンパク質結晶化 / ゲル / ゼオライト / 金属有機構造体

Outline of Final Research Achievements

A simple technique for protein crystallization in ionically cross-linked polysaccharide (alginate and carrageenan) gel capsules has been developed for contactless handling of crystals in X-ray crystallography. This method is designed to reduce mechanical damage to crystals caused by physical contact between crystal and mount tool and by osmotic shock during various manipulations including cryoprotection, heavy-atom derivatization and ligand soaking experiments. In this study, ten test proteins could be successfully crystallized in gel capsules. Two complete diffraction data sets from crystals of proteins in gel capsules were collected at 100 K without removing the crystals, showing that the crystals had low mosaicities. To demonstrate heavy-atom derivatization, lysozyme crystals were successfully derivatized with Pt atoms within alginate gel capsules. These results suggest that gel capsules prevent serious damage to protein crystals during such experiments.

Free Research Field

構造生物学