title: Tissue Specificity of Human Angiotensin I-Converting Enzyme.
abstract: BACKGROUND
  Angiotensin-converting enzyme (ACE), which metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling, as well as in reproductive functions, is expressed as a type-1 membrane glycoprotein on the surface of endothelial and epithelial cells. ACE also presents as a soluble form in biological fluids, among which seminal fluid being the richest in ACE content - 50-fold more than that in blood.
  
  
  RESULTS
  We performed conformational fingerprinting of lung and seminal fluid ACEs using a set of monoclonal antibodies (mAbs) to 17 epitopes of human ACE and determined the effects of potential ACE-binding partners on mAbs binding to these two different ACEs. Patterns of mAbs binding to ACEs from lung and from seminal fluid dramatically differed, which reflects difference in the local conformations of these ACEs, likely due to different patterns of ACE glycosylation in the lung endothelial cells and epithelial cells of epididymis/prostate (source of seminal fluid ACE), confirmed by mass-spectrometry of ACEs tryptic digests.
  
  
  CONCLUSIONS
  Dramatic differences in the local conformations of seminal fluid and lung ACEs, as well as the effects of ACE-binding partners on mAbs binding to these ACEs, suggest different regulation of ACE functions and shedding from epithelial cells in epididymis and prostate and endothelial cells of lung capillaries. The differences in local conformation of ACE could be the base for the generation of mAbs distingushing tissue-specific ACEs.
authors.affiliation: Chemical Faculty, M.V.Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Kryukova
authors.affiliation: Chemical Faculty, M.V.Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Tikhomirova
authors.affiliation: Bakulev Center for Cardiovascular Surgery, Moscow, Russia.
authors.forename: Elena Z
authors.initials: EZ
authors.lastname: Golukhova
authors.affiliation: Institute of Urology, Moscow, Russia.
authors.forename: Valery V
authors.initials: VV
authors.lastname: Evdokimov
authors.affiliation: Department of Medicine, Columbia University, New York, NY, United States of America.
authors.forename: Gavreel F
authors.initials: GF
authors.lastname: Kalantarov
authors.affiliation: Department of Medicine, Columbia University, New York, NY, United States of America.
authors.forename: Ilya N
authors.initials: IN
authors.lastname: Trakht
authors.affiliation: Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, United States of America.
authors.forename: David E
authors.initials: DE
authors.lastname: Schwartz
authors.affiliation: Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, United States of America.
authors.forename: Randal O
authors.initials: RO
authors.lastname: Dull
authors.affiliation: Chemical Faculty, M.V.Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Gusakov
authors.affiliation: Chemical Faculty, M.V.Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Uporov
authors.affiliation: Chemical Faculty, M.V.Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Olga A
authors.initials: OA
authors.lastname: Kost
authors.affiliation: Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, United States of America.
authors.forename: Sergei M
authors.initials: SM
authors.lastname: Danilov
mesh_terms: D000911:Antibodies, Monoclonal; D042783:Endothelial Cells / Q000378:metabolism; D004822:Epididymis / Q000378:metabolism; D018604:Epitope Mapping; D006801:Humans; D008168:Lung / Q000378:metabolism; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D011467:Prostate / Q000378:metabolism; D012661:Semen / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; C488034:ACE protein, human; D007703:Peptidyl-Dipeptidase A