PAS-positive Proteins Research Articles

Characterization of cortical secretory vesicles from the sea urchin egg

In order to evaluate the potential role of cortical vesicle exocytosis in modifying the egg surface at fertilization, we have begun characterization of the cortical secretory vesicle. Earlier reports ( N. K. Detering, G. L. Decker, E. D. Schmell, and W. Lennarz, 1977, J. Cell Biol. 75, 899–914) have described the isolation of an egg cell surface complex which consists of the egg plasma membrane and cortical secretory vesicles. We have now developed a method of disassembling the cell surface complex and isolating the cortical vesicles. The very low levels of contaminating plasma mebrane in this preparation allow the meaningful comparison of plasma membrane and cortical vesicle proteins and lipids. The cortical vesicles were found to be rich in high-molecular-weight PAS-positive proteins. The majority of these glycoconjugates were solubilized by hypotonic lysis of the cortical vesicles and probably represent proteins sequestered inside the intact vesicles. The fatty acid composition of the cortical vesicles was found to be unusually high in arachidonic acid. The fatty acid composition of the cortical vesicles was closely similar to that of the plasma membrane; however, the cortical vesicles were substantially higher in cholesterol content.

Electrophoretic study of nervous tissue proteins from invertebrate and vertebrate animals

1. 1. The proteins in the nervous tissue of four invertebrates (earthworm, snail, crab, starfish) and of six vertebrates (salamander, frog, tortoise, trout, pigeon, mouse) were sequentially extracted with hypotonic buffer, Triton X-100 and sodium dodecyl sulfate (SDS). 2. 2. The amount of aqueous-soluble proteins (hypotonic extract) ranges from 59 per cent (invertebrates) to 38 per cent (vertebrates). In contrast the vertebrates have a greater amount of membrane-bound proteins (Triton X-100 plus SDS extract), compared to the invertebrates, where the Triton extract, in particular, shows a doubling in protein content from 16 per cent in invertebrates to 34 per cent in vertebrates. 3. 3. The three extracts from each animal were examined by electrophoresis on polyacrylamide gels. Each extract shows a characteristic protein pattern, consisting of a multitude of bands, demonstrating that an animal species can be characterized by the protein composition of its nervous tissue extracts. 4. 4. Separated proteins, stained with PAS to localize glycoproteins, showed carbohydrate-containing material of low molecular weight to be present in the frontal bands of the Triton extracts. High molecular weight PAS-positive proteins were found in all three protein pools. 5. 5. The significance of these results is discussed.

The coelomic elements of sea urchins ( Strongylocentrotus and centrostephanus—VI. Cellulose-acetate membrane electrophoresis

1. 1. Electrophoretic patterns of proteins and acid mucopolysaccharides found in cell-free coelomic fluid and extracts of ceolomic cells of Strongylocentrotus franciscanus, S. purpuratus, and Centrostephanus coronatus differed according to the urchin species. Most of the proteins were PAS-positive. 2. 2. In cell-free coelomic fluid, echinochrome A (6-ethyl-2,3,7-trihydroxynaphthazarin) is bound to one or more PAS-positive proteins, according to the urchin species. The same proteins occur in echinochrome-free fluids. In cell extracts echinochrome occurs in PAS-positive proteins that also have an acid-mucopolysaccharide moiety. 3. 3. Purified echinochrome A conjugated with the proteins ovomucoid and calf-thymus histone, and with macromolecules in fresh cell-free sea-urchin coelomic fluid. It did not conjugate with bovine gamma globulin, or with molecules in concentrated coelomic fluid.

Verhalten der elektrophoretisch, biochemisch und immunologisch definierbaren proteine des sputums unter sekretolyse

Sputum samples of 20 patients with allergic asthma and the sputum pool of 10 healthy men were analysed before and after the application of a secretolytic agent. Each sputum sample was homogenized, the soluble proteins separated by agar- and immunelectrophoresis and then characterized biochemically. After secretolysis all primary demonstrable protein components showed a marked increase, especially the group of γ-globulins. These components proved as PAS-positive proteins, as fractions with LDH- as well as esterase activity and among the immunoglobulins as γA- and γG-fractions. The results are discussed in the light of the existing literature.

The periodic acid-Schiff reaction in the adrenal medulla. A histochemical and biochemical reappraisal.

The PAS reaction in the adrenal medulla of rat, rabbit, hamster, ox, pig and sheep was investigated. The medullary cells were positive in cryostat sections and potassium dichromate fixed material but not in formaldehyde fixed paraffin sections. The latter result is due mostly to the extraction of PAS positive lipids and loss of PAS positive proteins. No glycogen was detected in the chromaffin cells histochemically. The catechol amines played no part in the PAS reaction unless the fixative contained dichromate. The connective tissue elements were also PAS positive, and the nerve fibres in ox, sheep and pig. Periodate cannot be used to differentiate between adrenaline and noradrenaline storing cells.