title: Cathepsin B and complement C3 are major comigrants in the estrogen-induced peroxidase fraction of rat uterine fluid.
abstract: The luminal fluid of estrogen or DES-stimulated uterus of immature rats contains 10-12 isoforms of peroxidase between pI 4.5-6.0. N-terminal amino acid sequencing of diaminobenzidine-peroxidase bands eluted from IEF and SDS-PAGE gels showed the presence of cathepsin B and the complement family of proteins as the major comigrants. Sequential treatment of uterine fluid by cation, anion, and size exclusion chromatography resulted in a five-fold purification of peroxidase having a specific activity of 273 units/mg. Mass spectrometric studies of bands isolated from SDS-PAGE gels from the size-exclusion purified peroxidase fraction showed the presence of complement C3 along with novel previously uncharacterized proteins. Two dimensional electrophoresis followed by N-terminal amino acid sequencing confirmed the presence of cathepsin B isoforms and isoforms of a novel protein at approximately 87 kDa. Identification by mass spectrometry from the database for this novel protein was inconclusive but could most likely be a candidate for estrogen-induced peroxidase. Results conclusively prove that cathepsin B and complement C3 are major proteins in the estrogen-induced peroxidase fraction of uterine fluid.
authors.affiliation: Department of Biology, Howard University, Washington, DC, USA.
authors.forename: K V
authors.initials: KV
authors.lastname: Balan
authors.forename: V W
authors.initials: VW
authors.lastname: Hollis
authors.forename: W R
authors.initials: WR
authors.lastname: Eckberg
authors.forename: F
authors.initials: F
authors.lastname: Ayorinde
authors.forename: J D
authors.initials: JD
authors.lastname: Karkera
authors.forename: J H
authors.initials: JH
authors.lastname: Wyche
authors.forename: W A
authors.initials: WA
authors.lastname: Anderson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001826:Body Fluids / Q000737:chemistry / Q000378:metabolism*; D002401:Cathepsin B / Q000737:chemistry / Q000378:metabolism*; D002850:Chromatography, Gel; D003176:Complement C3 / Q000378:metabolism*; D004054:Diethylstilbestrol / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology; D005260:Female; D008969:Molecular Sequence Data; D009195:Peroxidase / Q000096:biosynthesis* / Q000302:isolation & purification; D020033:Protein Isoforms; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014599:Uterus / Q000187:drug effects / Q000378:metabolism*
chemical_list: D003176:Complement C3; D004968:Estrogens, Non-Steroidal; D020033:Protein Isoforms; D004054:Diethylstilbestrol; D009195:Peroxidase; D002401:Cathepsin B