Structure of catecholamine secretory vesicles from PC12 cells. Academic Article uri icon

Overview

abstract

  • Catecholamine secretory organelles were partially purified from PC12 cells. Measurement of the sedimentation coefficient (540S in 0.32 M sucrose), density in an isoosmotic gradient (1.139 g/cm), and density in an isoosmotic gradient using D2O as a solvent (1.205 g/cm3) have allowed us to calculate the molecular weight (1.17 X 10(9) daltons), radius (74 nm), and water content (62% vol/vol) of the secretory vesicle. The vesicle appears to contain ATP, but the molar ratio of 3,4-dihydroxyphenylethylamine (dopamine) to ATP in the particles is high (16.5) and the ATP was frequently asymmetrically distributed in the vesicle fraction. The particle behaves like a true secretory particle in that the dopamine content of the particle is increased by pargyline, diminished by depolarization, and abolished by reserpine. Sequential purification of PC12 lysates on controlled pore glass columns and isoosmotic Ficoll gradients produced a 20-30-fold purification, but this enrichment is not sufficient to produce a homogeneous population of vesicles. An 82,000-dalton protein copurifies with secretory granules and appears to be the major secreted protein. At this stage of purification this single protein makes up about 30% of the protein in the vesicle-containing fractions and so the vesicles must be approaching homogeneity.

publication date

  • October 1, 1985

Research

keywords

  • Adrenal Gland Neoplasms
  • Catecholamines
  • Cytoplasmic Granules
  • Pheochromocytoma

Identity

Scopus Document Identifier

  • 0022182431

Digital Object Identifier (DOI)

  • 10.1111/j.1471-4159.1985.tb05549.x

PubMed ID

  • 4031888

Additional Document Info

volume

  • 45

issue

  • 4