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Proton nuclear magnetic resonance of histidine residues in reindeer pancreatic ribonuclease
Author(s) -
den Berg Gita Leijenaar-Van,
Migchelsen C.,
Beintema J.J.
Publication year - 1974
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(74)80471-0
Subject(s) - histidine , bovine pancreatic ribonuclease , nuclear magnetic resonance , ribonuclease , proton , chemistry , biochemistry , physics , nuclear physics , enzyme , rna , gene
The pK values of the four histidines at positions 12, 48, 105, and 119 in bovine pancreatic ribonuclease have been determined from the titration behaviour of the Cc,) proton resonances in the n.m.r. spectrum of this protein [l-3] . Similar experiments performed on rat pancreatic ribonuclease showed many differences between the n.m.r. properties of the histidines in bovine and rat ribonuclease [4]. A study of the histidine resonances in chinchilla and coypu pancreatic ribonucleases led to a tentative assignment of these resonances to the four histidines at positions 12,48,80, and: 119 in these two enzymes [4] A titration curve with a high pK value (Coypu: 8.0; chinchilla: 7.2) has been tentatively assigned to histidine 80 in both enzymes. Pancreatic ribonuclease from most mammalian species contain a histidine residue at position 80 [5-7, unpublished]. Bovine and rat ribonuclease are two of the few exceptions. Ribonucleases from deer species differ relatively little in amino acid sequence from bovine ribonuclease [6, unpublished] and possess a histidine at position 80. So, an investigation of the histidine resonances in a deer ribonuclease can give us more information about the properties of a histidine residue at position 80. In this article we describe the n.m.r. properties of the histidine residues in the pancreatic ribonuclease from reindeer (Rangifer tarundus). The amino acid sequence of this enzyme has been determined recently (unpublished). Histidines occur at positions 12,48, 80,105, and 119. 2. Materials and methods