Live Chat
Today's Hours: 8:00am - 10:00pm
Lane Medical Library

Search

Filter Results

Did You Mean:

Search Results

Sort by
relevance
  • Database
    Summary: Aims to provide life science researchers with a comprehensive collection of experimental protocols free of charge. Each biomedical protocol published on our website bears high standards in quality and provides accurate and detailed guidance which allows even rookie researchers to easily repeat experiments.
    Digital Access Database
  • Article
    Parks LC, Niederman RA.
    Biochim Biophys Acta. 1978 Jul 20;511(1):70-82.
    The separation of membrane fragments was investigated in extracts of phototropically grown Rhodopseudomonas sphaeroides to determine if the plasma membrane contains discrete regions. A highly purified fraction of bacteriochlorophyll alpha-deficient membrane fragments was isolated by differential centrifugation, chromatography on Sepharose 2B, reaggregation, and isopycnic sedimentation on sucrose gradients. Significant levels of b- and c-type cytochromes and succinate dehydrogenase were demonstrated in the isolated membrane fragments and their appearance in electron micrographs, their polypeptide profile in dodecyl sulfate-polyacrylamide gel electrophoresis, and overall chemical composition were essentially identical to a similar fraction isolated from aerobically grown cells. Their polypeptide profiles were distinct from those of the intracytoplasmic chromatophore and outer membranes, and on the basis of bacteriochlorophyll content the phototrophic fraction was contaminated with chromatophores by less than 9%. The membrane fragments contained no diaminopimelic acid or glucosamine. It is condluded that the membrane fragments isolated from phototrophically growing Rp. sphaeroides have arisen from photosynthetic pigment-depleted regions of the plasma membrane structurally and functionally differentiated from the intracytoplasmic chromatophore membrane. These regions represent conserved chemotrophic cytoplasmic membrane whose synthesis continues under photoheterotrophic conditions.
    Digital Access Access Options