Image credit: Junko Okuda-Shimazaki, Hiromi Yoshida, Inyoung Lee, Katsuhiro Kojima, Nanoha Suzuki, Wakako Tsugawa, Mitsugu Yamada, Koji Inaka, Hiroaki Tanaka & Koji Sode. Microgravity environment grown crystal structure information based engineering of direct electron transfer type glucose dehydrogenase. Communications Biology, 5, Article number: 1334, December 6, 2022. DOI: 10.1038/s42003-022-04286-9 Figure 1. (a)

Okuda-Shimazaki et al report the partial crystal structure of B. cepacia glucose dehydrogenase (BcGDH) heterotrimer complex in the Journal of Communications Biology 5, Article number 1334, published December 6, 2022. BcGDH crystals were grown at the International Space Station using a counter-diffusion method in microgravity. The conditions of the crystal growth had a protein concentration of 5 mg/ml in 10 mM potassium phosphate pH 7.0 with 0.03% w/v DDM and a reservoir containing 2% v/v Tacsimate, 16% w/v PEG 3350, 0.03% w/v DDM, and 100 mM sodium citrate pH 5.6. 

Normal gravity laboratory conditions were not able to produce any crystals with sufficient diffraction. The microgravity suppressed the effects of convection in the liquid solution, allowing high quality protein crystals without any cracks to be obtained. This research adds microgravity to the crystallization toolbox for others to explore with.