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K Otto

Publications and source records attributed to K Otto.

At least 73 records · Page 4Linked to original sources
PubMed1976

On the specificity of bovine spleen cathepsin B2.

The specificity of bovine spleen cathepsin B2 has been investigated by means of some natural oligo- and polypeptides, i.e. glucagon, melittin, insulin A and B chain, bradykinin, angiotensin I and II, oxytocin ACTH, clupein and salmin. The enzyme is primarily a carboxypeptidase which hydrolyzes peptide linkages of most amino acids common to proteins. In addition, cathepsin B2 displays amidase and esterase activity without requiring a free carboxyl group. The main pH optimum is between 4 and 5, in some cases higher.

Animals↗
PubMed1975

Improved purification of cathepsin B1 and cathepsin B2.

An improved purification of the cathepsins B1 and B2 from bovine spleen is described. In addition to the formerly used procedure, chromatography with DEAE-Sephadex or -cellulose and mercurated agarose is used. Both enzymes are obtained in an electrophoretically pure form but consist of two or more isoenzymes. The isolation procedure leads to enzymes with high specific activities in satisfactory yields. Cathepsin B1 is frequently accompanied by small amounts of an arylamidase-like enzyme that hydrolyzes leucine p-nitroanilide. However, very probably, cathepsin B1 itself has a low activity toward this substrate too. Cathepsin B2 has a comparatively high activity with its characteristic though not specific substrate, alpha-N-benzoyl-L-arginineamide, whereas the activity toward haemoglobin is far lower. Both enzymes possess an essential SH group and require EDTA and a mercaptane for full activity, but their stability is markedly impaired by storage at higher thiol concentrations; Some other properties of the enzymes are also discussed.

Animals↗