Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Membrane glycoproteins have been studied in the normal lactating mammary gland and R3230 AC mammary tumor of the rat. Plasma membrane-enriched fractions were obtained from these tissues by discontinuous sucrose gradient centrifugation of a microsomal preparation from the tissue homogenates. The lightest membrane fractions (F-1 and F-2) have the greatest enrichment of plasma membrane markers, with a 14- to 20-fold purification of 5'-nucleotidase and Na+-K+ -adenosine triphosphatase over the homogenate values in both tumor and normal tissues for F-1. Electron microscopy shows smooth membrane vesicles for these fractions. Polypeptide analysis by acrylamide gel electrophoresis shows essentially the same patterns for F-1 and F-2 and only relatively minor differences between membrane components of tumor and normal tissues. Glycoprotein analysis of the polyacrylamide gels by periodate-Schiff staining indicates more dramatic differences. Membrane Fraction F-1 from normal tissue contains two major glycoproteins, GP-II and GP-III, while Fractions F-2 and F-3 contain an additional glycoprotein, GP-I, with a higher apparent molecular weight. In the tumor, the component corresponding to GP-III is decreased or absent and a new component GP-IV is seen at a lower apparent molecular weight.
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PMID:Membrane glycoprotein differences between normal lactating mammary tissue and the R3230 AC mammary tumor. 12 79

Mitochondria from a rat mammary tumor (R3230AC) have been compared with mitochondria from pregnant and lactating rat mammary glands, with particular attention paid to inner membrane enzymes and Transport proteins. In the tumor the mitochondrial adenosine triphosphatase was not activated by 2,4-dinitrophenol, in contrast to the mammary mitochondria from lactating or pregnant rats. Translocation of adenosine diphosphate across the inner membrane was found to be more rapid in the tumor by virtue of lovered Km adenosine diphosphate and raised Vmax. Transport of phosphate and dicarboxylic acids occurred at similar rates in all three types of mitochondria. The inner membrane proteins were also examined directly by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and some differences are noted. These results, although they indicate subtle differences between the inner mitochondrial membranes of tumor as compared with those of pregnant or lactating rat mammary glands, cannot form the basis of an explanation for enhanced glucose utilization and aerobic lactic acid production in this tumor.
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PMID:A comparative study of inner membrane enzymes and transport systems in mitochondria from R3230AC mammary tumor and normal rat mammary gland. 16 45