title: Molecular mapping of pulmonary endothelial membrane glycoproteins of the intact rabbit lung.
abstract: To study the biochemical characteristics of endothelium in vivo, we radioiodinated endothelial membrane proteins of the perfused rabbit lung using a water soluble analog of the Bolton-Hunter reagent, 125I-sulfosuccinimidyl (hydroxyphenyl) propionate (125I-s-SHPP). This technique led to a 10-fold increase in specific activity of radioiodinated lung membrane protein compared with our previously reported method using lactoperoxidase and glucose oxidase-catalyzed radioiodination. Tissue autoradiography confirmed that radioiodination was largely confined to the endothelium. Perfusion pressure, wet-to-dry weight ratios, and the morphological appearance of the lungs were within normal limits, indicating that the procedure does not cause apparent lung injury. Lectin binding to a crude membrane fraction of 125I-s-SHPP labeled lung led to isolation of several putative endothelial membrane proteins. Immunoprecipitation studies with appropriate antibodies enabled the identification of radioiodinated angiotensin-converting enzyme and beta 2-microglobulin associated major histocompatibility complex class I molecules in the membrane fraction. This technique will be useful for studying biochemical responses of the endothelium in vivo to a variety of pharmacological and physiology stimuli.
authors.affiliation: Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06510.
authors.forename: M P
authors.initials: MP
authors.lastname: Merker
authors.forename: W W
authors.initials: WW
authors.lastname: Carley
authors.forename: C N
authors.initials: CN
authors.lastname: Gillis
mesh_terms: D000818:Animals; D001345:Autoradiography; D004727:Endothelium / Q000032:analysis; D007457:Iodine Radioisotopes; D008168:Lung / Q000032:analysis*; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D007703:Peptidyl-Dipeptidase A / Q000032:analysis; D011233:Precipitin Tests; D011817:Rabbits; D013388:Succinimides
chemical_list: D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D013388:Succinimides; C017730:N-succinimidyl-3-(4-hydroxyphenyl)propionate; D007703:Peptidyl-Dipeptidase A