Sukumar Medda

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The glycoprotein egasyn complexes with and stabilizes precursor beta-glucuronidase in microsomes of several mouse organs. Several observations indicate egasyn is, in addition, an esterase. Liver homogenates of egasyn-positive strains have specific electrophoretically separable esterases which are absent in egasyn-negative mice. These esterases react with(More)
Recent experiments have demonstrated that egasyn not only sequesters β-glucuronidase in microsomes by forming high molecular weight complexes with β-glucuronidase, but also has carboxyl esterase activity. We have found several new phenotypes of egasyn-esterase after electrophoresis and isoelectric focusing of liver homogenates and purified egasyn of inbred(More)
Mouse liver beta-glucuronidase is stabilized within microsomal vesicles by complexation with the accessory protein egasyn. The location of the beta-glucuronidase-egasyn complex and free egasyn within microsomal vesicles was investigated. Surprisingly, it was found that neither the complex nor free egasyn are intrinsic membrane components. Rather, both are(More)
Osteoblasts undergo a temporal sequence of development characterized by transcriptional upregulation of osteoblast-specific genes. Basic helix-loop-helix (bHLH) transcription factors may control this developmental process through binding to E-box cis-acting elements in developmentally regulated genes. To investigate the role of bHLH proteins in MC3T3-E1(More)
Organophosphorous compounds, which are potent inhibitors of egasyn-esterase activity, caused a rapid dissociation of the high molecular weight egasyn-microsomal beta-glucuronidase complex when administered in vivo or when added in vitro to microsomal suspensions. The dissociation was relatively specific to phosphodiester inhibitors of the esterase active(More)
We report biochemical, immunological, and genetic studies which demonstrate that an accessory protein with the essential features of mouse egasyn is complexed with and stabilizes a portion of beta-glucuronidase in microsomes of rat liver. The accessory protein exists as a complex with beta-glucuronidase since it coprecipitates with beta-glucuronidase after(More)
We report biochemical, immunological, and genetic studies which demonstrate that an accessory protein with the essential features of mouse egasyn is complexed with and stabilizes a portion of @-glucuronidase in microsomes of rat liver. The accessory protein exists as a complex with &glucuronidase since it coprecipitates with ,&glucuronidase after treatment(More)
The proenzyme form of beta-glucuronidase is compartmentalized in large quantities within the endoplasmic reticulum by binding to the esterase, egasyn. Also, the propeptide of the proenzyme form of beta-glucuronidase is likely located at the carboxyl terminus. We have, therefore, tested if this carboxyl-terminal peptide is important in binding to egasyn. A(More)
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