Protoplast fractionation techniques were used to prepare subcellular fractions of three strains of Staphylococcus aureus for the analysis of alpha-hemolysin activity. More than 90% of the cellular hemolytic activity was localized in the periplasm, only a trace was detected in the cytoplasm, and none was found in either plasma membranes or mesosomes. This cellular portion constituted approximate...

Among the members of the prohormone convertase (PC) family, PC2 has a unique maturation pattern: it is retained in the ER for a comparatively long time and its propeptide is cleaved in the TGN/ secretory granules rather than in the ER. It is also unique by its association with the neuroendocrine protein 7B2. This interaction results in the facilitation of proPC2 maturation and in the production...

Discontinuous Ficoll-sucrose gradients were used to prepare subcellular fractions from mouse cerebral cortex at various stages of postnatal development. Representative samples of each subcellular fraction were obtained by sedimentation in an analytical ultracentrifuge and each fraction was examined quantitatively and qualitatively by electron microscopy. The amount of synaptosomal material was ...

Human parathyroid glands from a patient with chronic renal failure were used to study in vitro biosynthesis of immunoreactive parathyroid hormone. Parathyroid glands were incubated in the presence of [(3)H]leucine, and classical subcellular fractions were prepared. peptides from acetic acid extractions of the fractions were separated on Sephadex G-75 Superfine. Eluates were assayed for immunore...

1. The properties of rat brain lysophospholipase were investigated. Three subcellular fractions were employed: a particulate preparation which sedimented at 26,000 X g, a microsomal preparation which sedimented at 100,000 X g, and the supernatant of the above. The soluble enzyme represented only a small fraction of the total activity; it was further purified by treatment with protamine and ammo...

The amounts of protein, RNA (ribonucleic acid), virus, and the rate of incorporation of Pa* into RNA were determined in various subcellular fractions of HeLa cells at various times during a single sequence of infection with poliovirus. From these data interpretations are drawn concerning the biosynthesis at the cellular level of protein and RNA which are induced by virus infection. Within 1 hou...

smaller particles but did not solubilize them. Much less gangliosides were extracted after ultrasonic treatment of homogenates containing nuclei. 5. The effect of added agents and various treatments to homogenates on the quantity of gangliosides extracted from particulate and supernatant fractions was studied. 6. Addition of protamine or histone completely prevented the extraction of gangliosid...

glucose-6-phosphatase was determined in order to ascertain the nomenclature of each fraction. Renin content in these extracts as well as the extract of whole kidney was determined. In the subcellular fractions, renin content in lysosomal fraction was 1.10•}0.25ƒÊg, mitochondrial fraction 0.60•}0.12ƒÊg, mitochondrial-microsomal fraction 0.18•}0.01ƒÊg, microsomal fraction 0ƒÊg and soluble fractio...

The almost unique localization of hydroxyproline in collagen and the availability of methods for the assay of the imino acid offer a convenient approach to studies on this protein. In the experiments described here, L-proline-Cl4 was injected into embryonated eggs, and the specific activities of protein-bound proline and hydroxyprolinei in various subcellular fractions of the embryo were determ...

Mature adult male rats and castrated and testosterone-treated castrated adult rats were injected with pilocarpine HCl and 3-H-lysine and sacrificed sequentially over an eight-hour time period. Following homogenization and differential centrifugation, three subcellular fractions from each group of animals were analyzed by gel electrophoresis and liquid scintillation. Two proteins in the granule-...