Characterization of dislocations in monoclinic hen egg-white lysozyme crystals by synchrotron monochromatic-beam X-ray topography

Dislocations in monoclinic hen egg-white lysozyme crystals were investigated by means of synchrotron monochromatic-beam X-ray topography. The loop and curved dislocations were observed to be predominant in the crystals. Almost all the dislocations lay in (101̄) crystallographic plane, which corresponds to that with smallest slicing energy estimated by macrobond approach. One of the Burgers vectors of the dislocations was determined to be [010], which corresponds to the smallest lattice translational vector on the (101̄) plane. It is suggested that the loop and curved dislocations are slip ones introduced by a stress concentration during or after the growth.