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...

Coxiella burnetii isolates from a variety of clinical and geographical sources were screened for antigenic variation of lipopolysaccharides (LPSs) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis coupled with silver staining or immunoblotting. All isolates from chronic Q fever or other sources possessed a phase I-type LPS. These LPSs appeared to fall into three groups based on the s...

Membrane immunoglobulin (Ig) of splenocytes and thymocytes of the goldfish, Carassius auratus, was demonstrated by indirect fluorescent-antibody techniques. Observations on shedding and resynthesis indicated that the thymocyte Ig was endogenously produced. The lymphocyte surface proteins were radioiodinated using the lactoperoxidase-catalyzed reaction, and the labeled Ig molecules were isolated...

Vibrational sum frequency generation spectroscopy is used to study the interactions of the charged soluble organic surfactant sodium dodecyl sulfate (SDS) with an insoluble 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayer at the air-aqueous interface. Results indicate that the surfactant species compete for surface sites in the mixed system, with a lower monolayer number density of ...

The glycine receptor of rat spinal cord was solubilized with the nonionic detergent Triton X-100 and subsequently purified by affinity chromatography on aminostrychnine-agarose and wheat germ agglutininSepharose. An overall purification of 1950-fold was achieved. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and mercaptoethano1 revealed three glycine receptor-asso...

Membrane fraction RNA isolated from rat pituitary tumor (GC) cells has been translated in a wheat germ extract. A product was synthesized which was immunologically related to growth hormone, but which migrated more slowly than growth hormone upon sodium dodecyl sulfate-acrylamide gel electrophoresis. The mobility of the cell-free product on gels of this type was unchanged by treatment with eith...

In order to understand better the regulation of human placental proteins the activity of placental lactogen messenger RNA has been examined. Total RNA was extracted from normal term placentas and purified by chromatography on oligo(dT)-cellulose. The poly(A)-containing fraction stimulated amino acid incorporation 5- to 10-fold in wheat germ cell-free extracts, and immunoprecipitation of the tra...

Ribosome-inactivating proteins (RIPs) are N-glycosidases that remove a specific adenine from the sarcin/ricin loop of the large rRNA, thus arresting protein synthesis at the translocation step. In the present study, a protein termed tobacco RIP (TRIP) was isolated from tobacco (Nicotiana tabacum) leaves and purified using ion exchange and gel filtration chromatography in combination with yeast ...