The overall shape of the virions after purification and visualization ( e . g ., by ultracentrifugation and electron microscopy, respectively ) varies considerably; simple cylinders are far less prevalent than structures showing reversed direction, branches, and loops ( e . g ., U-, shepherd's crook-, 9-or eye bolt-shapes, or other or circular / coiled appearances ), the origin of which may be in the laboratory techniques applied.
22.
He established 4 classes of proteins : water-soluble albumins; salt soluble globulins : vicilin typically having sedimentation coefficients, S values ( a measure of the protein mass determined by sedimentation equilibrium ultracentrifugation ) of about 7 Svedberg units ( hence the common name 7S globulin ) and legumin ( 11S ); alcohol / water-soluble cereal prolamines; and a fourth class, glutelins, of difficultly soluble proteins no longer recognized and now considered low solubility prolamin or globulin storage proteins.
