title: Porcine pulmonary angiotensin I-converting enzyme--biochemical characterization and spatial arrangement of the N- and C-domains by three-dimensional electron microscopic reconstruction.
abstract: The somatic angiotensin I-converting enzyme (sACE; peptidyl-dipeptidase A; EC 3.4.15.1) was isolated from pig lung and purified to homogeneity. The purified enzyme has a molecular mass of about 180 kDa. Upon proteolytic cleavage, two approximately 90 kDa fragments were obtained and identified by amino-terminal sequence analysis as the N- and C-domains of sACE. Both purified domains were shown to be catalytically active. A 2.3 nm resolution model of sACE was obtained by three-dimensional electron microscopic reconstruction of negatively stained sACE particles, based on atomic X-ray data fitting. Our model shows for the first time the relative orientation of the sACE catalytically active domains and their spatial distance.
authors.affiliation: Development Center for Biotechnology, Taipei County 221, Taiwan, ROC.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Chen
authors.forename: Heinrich
authors.initials: H
authors.lastname: Lünsdorf
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Hecht
authors.forename: Hsin
authors.initials: H
authors.lastname: Tsai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002846:Chromatography, Affinity / Q000379:methods; D002847:Chromatography, Agarose / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007700:Kinetics; D008168:Lung / Q000201:enzymology*; D008854:Microscopy, Electron / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009842:Oligopeptides / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure*; D017434:Protein Structure, Tertiary; D020539:Sequence Analysis, Protein; D013552:Swine
chemical_list: D009842:Oligopeptides; C038275:2-furanacryloyl-phenylalanyl-glycyl-glycine; D007703:Peptidyl-Dipeptidase A