ISSN:
1573-4919
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Summary The presence of a high-molecular weight complex with acid phosphatase activity in the cytosol of human mammary tumors is reported. This complex appeared in the cytosol after tissue homogenization in the presence of dithiotreitol, with or without Triton X-100 and at acidic or neutral pH. Upon gel electrophoresis, this fraction showed only one band of enzyme activity which did not enter the fine pore gel. Lubrol or n-butanol had no apparent effect on this complex, and 8 M urea or 2% sodium dodecyl sulfate did not disaggregate this large molecule. After purification by gel filtration, ammonium sulfate precipitation and ion-exchange chromatography an apparent molecular weight or 106 was measured. It hydrolyzed typical acid phosphatase substrates such as p-NPP and α-NP, but also ATP and PPi. Only 44% inhibition was observed with L-(+)tartrate and it was still 40% active after 1 hr incubation at 60 °C. Reduction in the presence of SDS yielded several polypeptide bands. It was also detected in some samples of normal mammary tissues, but not in normal human placenta or liver.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00224771
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