Primary Structure of a Non-Secretory Ribonuclease from Bovine Kidney1

Abstract

The primary structure of a non-secretory ribonuclease from bovine kidney (RNase K2) was determined. The sequence determined was VPKGLTKARWFEIQHIQPRLLQCNKAMSGV NNYTQHCKPENTFLHNVFQDVTAVCDMPNIICKNGRHNCHQSPKPVNLTQCNFIAGRYPDC RYHDDAQYKFFIVACDPPQKTDPPYHLVPVHLDKYF. The sequence homology with human non-secretory RNase, bovine pancreatic RNase, and human secretory RNase are 46, 34.6, and 32.3%, respectively. The bovine kidney RNase has two inserted sequences, a tripeptide at the N-terminus and a heptapeptide between the 113th and 114th position of bovine pancreatic RNase; on the other hand, it is deleted of the hexapeptide consisting of the 17th to the 22nd amino acid residue of RNase A. The amino acid residues assumed to be the constituents of the bovine pancreatic RNase active site are all conserved except F120 (L in RNase K2).

C-Mannosylation of Human RNase 2 Is an Intracellular Process Performed by a Variety of Cultured Cells

“…It is of particular interest to note that in porcine kidney cells (LLC-PK 1 ) human RNase 2 was C-mannosylated at Trp-7 but that the homologous enzyme from porcine kidney contains an unmodified, basic amino acid at this position (26). Furthermore, Trp-10 in the latter RNases remains unmodified.…”

Human extracellular ribonucleases: multiplicity, molecular diversity and catalytic properties of the major RNase types

“…According to this classification [13] human ribonucleases not only found in pancreas but also in other tissues and fluids (characterized by showing sequences as well as stuctural and catalytic properties similar to those of bovine [14] or human [15 -17] pancreatic RNases) belong to the mammalian pancreatic-type (pt) RNase family. Consequently, the extracellular ribonucleases expressed in tissues other than pancreas and also found in several fluids (characterized by having sequence and catalytic properties similar to those of bovine kidney RNase k2 [18] or human eosinophil-derived neurotoxin (EDN)/ liver RNase [17,19,20]) constitute the nonpancreatictype (npt) RNase family. Here, as already suggested [13,17], the designations 'pt' and 'npt' have been adopted, which might be more appropriate and less confusing than the terms 'secretory' and 'nonsecretory' usually used in the past to indicate the two major classes of mammalian RNases.…”

Structure–function relationships in human ribonucleases: main distinctive features of the major RNase types

“…1) to pt/nptRNase 4, ptRNase 1, and nptRNase 2 (39%, 35%>, and 27% sequence identity, respectively [10,11,22,38]), angRNase 5 shows an unusual ribonucleolytic activity [40,41], which differs markedly both in magnitude and specificity from RNase activity of the other human RNases. The extremely weak ribonucleolytic activity (toward standard RNase substrates [40]) of angRNase 5 which is, however, essential for angiogenicity, seems to be in part due to the obstruction of the pyrimidine binding site (as observed in the homologous RNase A structure) by Gln-117 [42].…”