Scanning x-ray microdiffraction studies of the molecular architecture of biological tissues

Abstract

X-ray scattering is an important method to study atomic and molecular structures. Here, I apply scanning x-ray micro-diffraction, a new advanced synchrotron technology, to study the molecular structure of three tissues: 1. Myelin within the peripheral nervous system (PNS); 2. Plant cell walls in Arabidopsis stems; 3. Protein aggregation in human brain sections from Alzheimer's patients. A suite of custom software was developed to overcome the challenge of processing a large amount of data collected by scanning micro diffraction and to extract complex features from the scattering patterns of these different tissues. These improvements in software have greatly expanded the utility scanning microdiffraction technology for analysis of detailed information about the molecular architecture of myelin in the nodal, paranodal, and juxtaparanodal regions; the structural heterogeneities within the Arabidopsis stem; and pathological molecular structures that arise in Alzheimer's disease. We anticipate significant expansion of the use of this method for studies of the molecular architecture of intact tissues and the alteration of these structures due to wounds, specific mutations or pathological conditions.