Development of an X-ray fluorescence holographic measurement system for protein crystals

Experimental procedure and setup for obtaining X-ray fluorescence hologram of crystalline metalloprotein samples are described. Human hemoglobin, an α2β2 tetrameric metalloprotein containing the Fe(II) heme active-site in each chain, was chosen for this study because of its wealth of crystallographi...

Full description

Saved in:

Bibliographic Details
Published in:	Review of scientific instruments 2016-06, Vol.87 (6), p.063707-063707
Main Authors:	Sato-Tomita, Ayana, Shibayama, Naoya, Happo, Naohisa, Kimura, Koji, Okabe, Takahiro, Matsushita, Tomohiro, Park, Sam-Yong, Sasaki, Yuji C., Hayashi, Kouichi
Format:	Article
Language:	eng
Subjects:	BEAMS Catalytic Domain Cold flow Cold gas CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY CRYSTALLOGRAPHY CRYSTALS DAMAGE DATA ACQUISITION FLUORESCENCE GAS FLOW HEME HEMOGLOBIN Hemoglobins - chemistry HOLOGRAPHY Holography - methods Humans INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY METALLOPROTEINS METALS Proteins Radiation damage RADIATION EFFECTS Scientific apparatus & instruments Spectrometry, X-Ray Emission - methods STEREOCHEMISTRY X RADIATION X-ray fluorescence
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Experimental procedure and setup for obtaining X-ray fluorescence hologram of crystalline metalloprotein samples are described. Human hemoglobin, an α2β2 tetrameric metalloprotein containing the Fe(II) heme active-site in each chain, was chosen for this study because of its wealth of crystallographic data. A cold gas flow system was introduced to reduce X-ray radiation damage of protein crystals that are usually fragile and susceptible to damage. A χ-stage was installed to rotate the sample while avoiding intersection between the X-ray beam and the sample loop or holder, which is needed for supporting fragile protein crystals. Huge hemoglobin crystals (with a maximum size of 8 × 6 × 3 mm3) were prepared and used to keep the footprint of the incident X-ray beam smaller than the sample size during the entire course of the measurement with the incident angle of 0°-70°. Under these experimental and data acquisition conditions, we achieved the first observation of the X-ray fluorescence hologram pattern from the protein crystals with minimal radiation damage, opening up a new and potential method for investigating the stereochemistry of the metal active-sites in biomacromolecules.
ISSN:	0034-6748 1089-7623