Isolation and Characterization of Brain Endothelial Cells: Morphology and Enzyme Activity

SUMMARYFive clones of Chinese hamster ovary cells with increased resistance to bleomycin have been isolated following ethylmethanesulphonate mutagenesis. Resistance was stable in three of the clones, but unstable in the other two. One of the stably resistant clones was cross resistant to unrelated drugs, and in contrast to the parental cells, its response to bleomycin was potentiated by tween 80. These two observations suggested a membrane alteration in the resistant clone. There was no significant difference in bleomycin-inactivating enzyme activity between the parental and resistant clones.

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Isolation and Characterization of a Chlorogenic Acid Esterase from Aspergillus niger

Zeitschrift für Naturforschung C ◽

10.1515/znc-1980-3-407 ◽

1980 ◽

Vol 35 (3-4) ◽

pp. 209-212 ◽

Cited By ~ 17

Author(s):

B. Schöbel ◽

W. Pollmann

Keyword(s):

Enzyme Activity ◽

Chlorogenic Acid ◽

Divalent Cations ◽

Hydrolysis Product ◽

The Other ◽

Temperature Optimum ◽

Pig Liver ◽

Isolation And Characterization

Abstract The isolation and characterization of a specific chlorogenic acid esterase is described. The enzyme activity is measured by determination of the hydrolysis product caffeic acid. The enzyme had been concentrated by means of ultrafiltration and column-chromatography. The pH- and temperature optimum were 6.5 and 45 °C respectively. Divalent cations were not required for the enzyme activity. As other esterases, this enzyme is inhibited by di-isopropyl-phosphorofluoridate. The Km-value is 0.70 mᴍ chlorogenic acid, the molecular weight 240000. The described enzyme is specific for chlorogenic acid. On the other hand a typical unspecific esterase like the pig liver esterases does not split chlorogenic acid. The isoelectric focusing reveals several isoenzymes of chlorogenase within a pI-range of 4.0-4.5.

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Isolation and characterization of a rat cDNA clone encoding a secreted superoxide dismutase reveals the epididymis to be a major site of its expression

Biochemical Journal ◽

10.1042/bj2930021 ◽

1993 ◽

Vol 293 (1) ◽

pp. 21-25 ◽

Cited By ~ 53

Author(s):

A C F Perry ◽

R Jones ◽

L Hall

Keyword(s):

Lipid Peroxidation ◽

Superoxide Dismutase ◽

Enzyme Activity ◽

Sequence Analysis ◽

Cdna Clone ◽

Northern Blot ◽

Northern Blot Analysis ◽

Major Site ◽

Isolation And Characterization

Superoxide dismutase (SOD) plays a key role in combating loss of fertility of spermatozoa due to lipid peroxidation. Here we report the sequence of a cDNA encoding a secreted form of SOD isolated from a rat epididymal library. Northern-blot analysis indicates that the corresponding transcript is expressed principally in the cauda region of the epididymis, consistent with the high levels of SOD enzyme activity found in cauda-epididymidal plasma. Much lower levels of an identically sized transcript exist in all tissues examined, including placenta. PCR and subsequent sequence analysis of rat placental SOD strongly suggest that it is identical in sequence with epididymal SOD.

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