A new protein crystal mounting method using humid air and glue coating

Cryopreservation of protein crystals are a useful to reduce radiation damage for synchrotron experiments, the cryoloop mounting method using cryoprotectant agents is the widely used. However, Protein crystals are fragile, and they have often trouble to find a condition suitable for cryo-cooling. X-ray diffraction experiments at room temperature can evaluate the quality of the protein crystal and perform structural analysis without being affected shrink of the crystal by cryo-cooled and addition cryoprotectant agents. And, conventional humidity controlled method is possible to improve resolution of limited protein crystals [1]. However, protein crystals of these diffraction experiments cannot apply same mounting method. We developed a new crystal mounting method, the humid air and glue-coating (HAG) mounting method, which involves a combination of controlled adjustable humid air and water-soluble polymer glue for crystal coating [2]. By coating with the water-soluble polymer glue, most crystals exposed to the controlled humid air were stable at room temperature and could be cryocooled under optimized humidity without additional cryoprotectant agents. For example, the crystals of the bacterial hydrolase RsbQ was mechanically very fragile and sensitive to environmental changes. Thus, RsbQ crystal cannot apply cryoloop mount with cryoprotectant agents. By using the HAG method, we were able to obtain 1.4 Å data and solve its structure. For another example, membrane protein crystal was improved resolution to optimize humidity. The crystals by using HAG method reproducibly showed crystal lattice transformation in response to a change in humidity, thus using this method a series of isomorphic crystals can be prepared. We introduce HAG method, and demonstrate its success with various protein crystals.

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Preparation and Properties of the ZnO Nanopowder with Chemical Liquid-Phase Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.412.9 ◽

2011 ◽

Vol 412 ◽

pp. 9-12

Author(s):

Zhong Zhou Yi ◽

Bo Wang ◽

Feng Rui Zhai ◽

Zhi Peng Xie

Keyword(s):

Liquid Phase ◽

Precursor Solution ◽

Water Soluble ◽

Phase Method ◽

X Ray Diffraction ◽

Soluble Polymer ◽

Water Soluble Polymer ◽

Liquid Phase Method ◽

Transmission Electron ◽

Zno Nanopowder

ZnO nanopowder have been prepared by chemistry liquid-phase method with the water soluble polymer and the surfactant as additive in [Zn (OH)4]2- precursor solution. The Character of spectroscopy and microstructure and phase composition was studied by X-ray diffraction, transmission electron microscopy and UV–Vis absorption spectroscopy. The possible influence like reaction time, reaction temperature, reactant ratios and so on was investigated. At the same time, the inorganic granule coring and the crystal growth affected by the water-soluble polymer and the surfactant were discussed. Studies have shown the ZnO nanopowder with the diameter of 50nm has the structure such as the good crystal state and well-defined crystallographic surfaces. The ZnO nanopowder have strong absorption in the UV region with the wavelength of 200 ~ 300 nm.

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Radiation damage in protein crystals examined under various conditions by different methods

Journal of Synchrotron Radiation ◽

10.1107/s0909049509005238 ◽

2009 ◽

Vol 16 (2) ◽

pp. 129-132 ◽

Cited By ~ 27

Author(s):

Elspeth F. Garman ◽

Colin Nave

Keyword(s):

Radiation Damage ◽

Electronic State ◽

Room Temperature ◽

Protein Crystal ◽

Protein Crystals ◽

X Rays ◽

X Ray Diffraction ◽

Radiation Physics ◽

X Ray ◽

The Past

Investigation of radiation damage in protein crystals has progressed in several directions over the past couple of years. There have been improvements in the basic procedures such as calibration of the incident X-ray intensity and calculation of the dose likely to be deposited in a crystal of known size and composition with this intensity. There has been increased emphasis on using additional techniques such as optical, Raman or X-ray spectroscopy to complement X-ray diffraction. Apparent discrepancies between the results of different techniques can be explained by the fact that they are sensitive to different length scales or to changes in the electronic state rather than to movement of atoms. Investigations have been carried out at room temperature as well as cryo-temperatures and, in both cases, with the introduction of potential scavenger molecules. These and other studies are leading to an overall description of the changes which can occur when a protein crystal is irradiated with X-rays at both cryo- and room temperatures. Results from crystallographic and spectroscopic radiation-damage experiments can be reconciled with other studies in the field of radiation physics and chemistry.

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Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

Materials Advances ◽

10.1039/d1ma00099c ◽

2021 ◽

Author(s):

Aranee Pleng Teepakakorn ◽

Makoto Ogawa

Keyword(s):

Vinyl Alcohol ◽

Aqueous Media ◽

Water Soluble ◽

Poly Vinyl Alcohol ◽

Self Healing ◽

Soluble Polymer ◽

Water Soluble Polymer ◽

Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

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