title: A comparison of four cathepsins (B, L, N and S) with collagenolytic activity from rabbit spleen.
abstract: We have separated four cathepsins (B, L, N and S) from rabbit spleen. They are all collagen-degrading cysteine proteinases, with Mr values of 25,250, 23,500, 34,000 and 30,000 for cathepsin B, L, N and S respectively. Cathepsins B, N and S have isoelectric points of 5.4, 6.2 and 6.8 respectively, whereas cathepsin L exhibited multiple charge forms in the range 5.0-5.7. A comparison of their specific activity against a variety of protein and synthetic substrates shows many differences. These differences can be visually illustrated through isoelectric focusing and detection of enzymic activity with protein and synthetic-substrate overlays. By using an enzyme-linked immunosorbent assay based on the binding to chicken cystatin and detection with polyclonal and monoclonal antibodies to native cathepsins B and L, no cross-reactivity of the four native enzymes was observed. Studies on the co-operative or synergistic effect in degrading collagen indicated that, of the different combinations tested, only the combination of cathepsin B and N exhibited enhanced collagenolysis.
authors.affiliation: A.F.R.C. Institute of Food Research Bristol Laboratory, Langford, Bristol, U.K.
authors.forename: R A
authors.initials: RA
authors.lastname: Maciewicz
authors.forename: D J
authors.initials: DJ
authors.lastname: Etherington
mesh_terms: D000818:Animals; D002401:Cathepsin B / Q000302:isolation & purification; D056668:Cathepsin L; D002403:Cathepsins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D003429:Cross Reactions; D003546:Cysteine Endopeptidases; D010450:Endopeptidases; D007525:Isoelectric Focusing; D011817:Rabbits; D013154:Spleen / Q000201:enzymology*
chemical_list: D003094:Collagen; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C028218:cathepsin N; D002401:Cathepsin B; D056668:Cathepsin L; C028217:cathepsin S