The sodiumand potassium-activated adenosine triphosphatase (Naf + K+)-ATPase was partially purified from a microsomal fraction of whole rabbit brain, homogenized in a deoxycholate buffer. Suspension and separation by flotation of the resulting lipoproteins in a linear gradient of potassium iodide formed the basis of a rapid preparative technique, whereby the enzyme-containing lipoproteins were ...

A particulate fraction of Erysipelothrix rhusiopathiae cultures has been subjected to butanol extraction and treatment with surface-active agents in an attempt to solubilize a protective antigen. The particulate fraction was partitioned into the butanol layer but was not solubilized. Only sodium dodecyl sulfate solubilized the particles. The soluble protective activity was not sedimented by cen...

Preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis has been used to purify digitonin extracts of rod outer segments of squid retinas. Besides rhodopsin the extracts contained small amounts of seven or eight contaminating proteins plus a light-stable pink-purple pigment identified as ommin. Reproducible amino acid analyses were obtained from separate purified preparations of o...

Cross-linked triclinic lysozyme was denatured with sodium dodecyl sulfate. Removal of the denaturant resulted in a refolding of the protein to a conformation similar to but not identical with the native one. Three-dimensional x-ray diffraction data out to 3.2-A resolution were collected for two states in the refolding pathway, and appropriately weighted electron density difference maps were con...

A rapid and convenient method for peptide mapping of proteins has been developed. The technique, which is especially suitable for analysis of proteins that have been isolated from gels containg sodium dodecyl sulfate, involves partial enzymatic proteolysis in the presence of sodium dodecyl sulfate and analysis of the cleavage products by polyacrylamide gel electrophoresis. The pattern of peptid...