title: Enzymatic and envelope-converting activities of pars recta oviductal fluid from Xenopus laevis.
abstract: Conversion of the coelomic egg envelope to the vitelline envelope of the Xenopus laevis egg is known to take place in the pars recta (PR) region of the oviduct. A method for collecting fluid generated from PR cultured in vitro was devised which enhanced the recovery of envelope-converting factors. By the criteria of melting temperature analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, 125I labeling, ferritin binding, and in vitro fertilization assays, the secretions collected from PR cultured in vitro were capable of modifying the envelope in a manner analogous to that which occurred in vivo, including the limited hydrolysis of one envelope glycoprotein. Hydrolytic activities present in PR fluid were assayed with a number of peptide and carbohydrate substrates. Enzymes which hydrolyzed t-butyloxycarbonyl-Leu-Ser-Thr-Arg-methylcoumarylamide, t-butyloxycarbonyl-Phe-Ser-Arg-methylcoumarylamide, and t-butyloxycarbonyl-Val-Leu-Lys-methylcoumarylamide were found to be present in PR fluid at levels elevated by threefold or more over amounts found in a comparable volume of blood plasma.
authors.affiliation: Department of Biochemistry and Biophysics, University of California, Davis 95616.
authors.forename: M A
authors.initials: MA
authors.lastname: Bakos
authors.forename: A
authors.initials: A
authors.lastname: Kurosky
authors.forename: J L
authors.initials: JL
authors.lastname: Hedrick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001826:Body Fluids / Q000502:physiology; D005306:Fertilization; D006023:Glycoproteins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007531:Isoflurophate / Q000494:pharmacology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010057:Oviducts / Q000033:anatomy & histology / Q000502:physiology*; D010063:Ovum / Q000502:physiology*; D012697:Serine Endopeptidases / Q000378:metabolism; D012995:Solubility; D013379:Substrate Specificity; D014982:Xenopus laevis / Q000502:physiology*
chemical_list: D006023:Glycoproteins; D007531:Isoflurophate; D012697:Serine Endopeptidases