title: Purification and some properties of ribonuclease from Xenopus laevis eggs.
abstract: A 122 kDa RNase from eggs of Xenopus laevis was purified by sequential chromatography on Sephadex G-75, DEAE-cellulose, heparin-Sepharose and TSK gel G3000SW columns, and gave a single 60 kDa band on SDS-polyacrylamide gel electrophoresis under reducing and nonreducing conditions. The RNase composed of two 60 kDa subunits is able to recognize pyrimidine bases specifically. The pH optimum of the RNase was 7.5 in Tris-HCl buffer. The enzyme activity was abolished by treatment at 80 degrees C for 5 min and pH 2 or 12 for 1 h. Since egg lectins with RNase activity obtained from Rana catesbeiana and R. japonica and bovine pancreatic RNase A show about 30% protein homology and these three proteins are 12-14 kDa heat-stable RNases, [K. Titani, K. Takio, M. Kuwada, K. Nitta, F. Sakakibara, H. Kawauchi, G. Takayanagi and S. Hakomori, Biochemistry, 26, 2189 (1987); Y: Kamiya, F. Oyama, R. Oyama, F. Sakakibara, K. Nitta, H. Kawauchi, Y. Takayanagi and K. Titani, J. Biochem. (Tokyo), 108, 139 (1990)], the data suggest that the X. laevis egg RNase is a unique protein compared with RNases from not only amphibians, but also mammals.
authors.affiliation: Cancer Research Institute, Tohoku College of Pharmaceutical Sciences, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nitta
authors.forename: K
authors.initials: K
authors.lastname: Ozaki
authors.forename: K
authors.initials: K
authors.lastname: Hagioita
authors.forename: Y
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Terasaki
authors.forename: N
authors.initials: N
authors.lastname: Suzuki
authors.forename: A
authors.initials: A
authors.lastname: Sano
authors.forename: M
authors.initials: M
authors.lastname: Hosono
authors.forename: H
authors.initials: H
authors.lastname: Kawauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Takayanagi
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002384:Catalysis; D002412:Cations / Q000494:pharmacology; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D010063:Ovum / Q000201:enzymology*; D011119:Polynucleotides / Q000378:metabolism; D012260:Ribonucleases / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D000596:Amino Acids; D002412:Cations; D011119:Polynucleotides; D012260:Ribonucleases