Primary structure of a ribonuclease from bullfrog (Rana catesbeiana) liver.
A pyrimidine base-specific ribonuclease was purified from bullfrog (Rana catesbeiana) liver by means of CM-cellulose column chromatography and affinity chromatography on heparin-Sepharose CL-6B, which gave single band on SDS-slab electrophoresis. The primary structure of the bullfrog liver RNase was determined. It consisted of 111 amino acid residues, including 8 half-cystine residues. From the sequence, it was concluded that three disulfide bridges in RNase A were conserved in the bullfrog RNase, that a disulfide bridge in RNase A [Cys65-Cys126 (RNase A numbering)] was deleted, and that a new disulfide bridge was created in the C-terminal part of the enzyme. In this frog RNase, the amino acid residues thought to be essential for catalysis in bovine pancreatic RNase A were conserved except for Asp121 (RNase A numbering). The sequence homology of the bullfrog liver RNase with bovine pancreatic RNase A was 30.6%. The sequence of bullfrog liver RNase was very similar to those of lectins obtained from bullfrog egg by Titani et al. [Biochemistry (1988) 26, 2189-2194] and R. japonica egg by Kamiya et al. [Seikagaku (in Japanese) (1989) 60, 733; and personal communication from Kamiya, Y., Oyama, F., Oyama, R., Sakakibara, F., Nitta, K., Kawauchi, H., and Titani, K.]. The sequence homology between the bullfrog liver RNase and the two lectins was 70.2 and 64.8%, respectively.
Nitta
R
R
Department of Microbiology, Hoshi College of Pharmacy, Tokyo.
Katayama
N
N
Okabe
Y
Y
Iwama
M
M
Watanabe
H
H
Abe
Y
Y
Okazaki
T
T
Ohgi
K
K
Irie
M
M
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000645:Ammonium Sulfate; D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid; D003488:Cyanogen Bromide; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D006902:Hydroxymercuribenzoates; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011892:Rana catesbeiana; D012260:Ribonucleases / Q000302:isolation & purification; D014357:Trypsin
D000596:Amino Acids; D006902:Hydroxymercuribenzoates; C030601:4-hydroxymercuribenzoate; D012260:Ribonucleases; D014357:Trypsin; D003488:Cyanogen Bromide; D000645:Ammonium Sulfate