Arylsulfatase multiplicity in Proteus rettgeri

Multiple electrophoretic species of arylsulfatase were demonstrated in sonicates of Proteus rettgeri by paper electrophoresis. Subsequent treatment of the sonicates with streptomycin sulfate and DEAE-cellulose chromatography resolved enzyme activity into four fractions. Electrophoretic examination of each chromatographic fraction revealed sulfatase heterogeneity comparable to that of the initial extract. These electrophoretic components differed in their general response to a number of arylsulfatase inhibitors. The results are discussed in relation to the finding of multiple species of arylsulfatase in other biological systems.

A new method for the preparation of rat liver lysosomes. Separation of cell organelles of rat liver by carrier-free continuous electrophoresis

A combination of differential centrifugation and carrier-free continuous electrophoresis is introduced as a new method for the isolation of animal cell organelles. Various buffers were systematically checked in order to find the system which preserves the organelles and gives as well a good separation in the free-flow electrophoresis apparatus. Triethanolamine-acetate buffer (10 mM), pH 7.4 was used. The isolated lysosomes were pure according to marker enzymes and electron micrographs. A heterogeneity of the lysosomes in electrophoretic mobility was demonstrated with respect to the marker enzymes arylsulfatase and beta-glucuronidase. The lysosomes with higher mobility showed a maximum enrichment of 240-fold with respect to arylsulfatase. The lysosomes with lower electrophoretic mobility showed a 65-fold enrichment with respect to beta-glucuronidase. The ratio of beta-glucuronidase to arylsulfatase varied from 2:1 to 1:2 in lysosomes of different mobility. The yield amounted to approximately 1 mg of lysosomal protein per gram of liver protein. 5-8 mg of lysosomes can be obtained in one experiment. The electrophoretic separation proves to be an effective tool in obtaining pure and well preserved lysosomes.

Enzymic degradation of keratosulphates

1. A multienzyme system capable of degrading keratosulphates to yield galactose, N-acetylglucosamine and sulphate was found in the liver extract of a marine gastropod, Charonia lampas. 2. During the degradation, neither oligosaccharides nor sulphated sugars were produced. 3. It is suggested that the degradation could be attributed to the concerted action of beta-galactosidase, beta-N-acetylglucosaminidase and a sulphatase (sulphohydrolase), tentatively designated keratosulphatase. 4. Two forms of keratosulphatase (I and II) were separated by DEAE-Sephadex column chromatography. Both forms could release all the sulphate from keratosulphates and neither appeared to be identical with glycosulphatase or chondrosulphatase, both of which are also present in Charonia lampas. 5. beta-Galactosidase and beta-N-acetylglucosaminidase could degrade keratopolysulphate to a greater extent in the presence of keratosulphatase than in its absence. 6. It is suggested that keratosulphate was first desulphated by the action of keratosulphatase, and the desulphated polymer was then degraded to galactose and N-acetylglucosamine by the action of beta-galactosidase and beta-N-acetylglucosaminidase. 7. beta-Galactosidase alone released a small amount of galactose from shark cartilage keratopolysulphate, but beta-N-acetylglucosaminidase alone did not release N-acetylglucosamine. This indicates that unsulphated galactose residues occupy all the non-reducing terminal positions in keratopolysulphate chains.

The isolation and characterization of lysosomal particles from myxamoebae of the cellular slime mould Dictyostelium discoideum

1. The myxamoebae of the cellular slime mould Dictyostelium discoideum possess several typically lysosomal enzyme activities. 2. These enzymes are present in the cell in association and in a lysosome-like particle. 3. The lysosomes of myxamoebae grown axenically have a different enzymic composition and a different density from those grown on bacteria. 4. During cell differentiation the specific activities of the lysosomal enzymes change. 5. It is suggested that both during growth and differentiation the amounts of lysosomal enzymes present in the cell are regulated.

Association of lysosomal enzymes in cultured fibroblasts with the intracellular growth of Mycobacterium lepraemurium

An established line of rat fibroblasts (14pf), growing in either of two media, was infected with Mycobacterium lepraemurium. One of the media (equal parts of human cord serum and Hanks' balanced salt solution) supports active intracellular bacterial multiplication, whereas the other (10 per cent calf serum in Eagle's medium with added peptone) fails to do so. Within 1 week of infection, the cells were stained for acid phosphatase, aryl sulphatase and β-galactosidase activities and examined by light microscopy. Cells in equal parts of cord serum and Hanks' balanced salt solution showed an accumulation of all 3 enzymes around the bacteria whereas cells in 10 per cent calf serum in Eagle's medium showed only light, diffuse, general staining with little localization around the bacteria. Cells in the former medium also had greater lysosomal activity before infection with Myco. lepraemurium than cells in the latter medium, showing that the increased activity was not the result of intracellular multiplication of the bacteria. It is concluded that the failure to support mycobacterial growth by the cells growing in the medium containing calf serum must be unconnected with direct lysosomal action. A possible beneficial effect of lysosomal enzymes on the growth of these obligate intracellular mycobacteria is suggested.