scholarly journals Studies on cathepsin B in human articular cartilage

1978 ◽  
Vol 171 (1) ◽  
pp. 149-154 ◽  
Author(s):  
M T Bayliss ◽  
S Y Ali

The thiol proteinase cathepsin B (EC 3.4.22.1), previously called cathepsin B1, was assayed in human articular cartilage by its hydrolysis of the synthetic substrate alpha-N-benzoyl-DL-arginine 2-naphthylamide. The enzyme was activated by cysteine and EDTA and completely inhibited by iodoacetamide and HgCl2. It was also partially inhibited by whole human serum. Human osteoarthrotic cartilage had increased activity when compared with normal cartilage. Cathepsin B activity of normal cartilage was age-related, being high in juveniles and declining to low values in adult and elderly individuals. Cathepsin D and cathepsin B both exhibited a zonal variation through the cartilage depth; the surface cells appeared to contain more activity than those close to the subchondral bone.

2000 ◽  
Vol 350 (2) ◽  
pp. 381 ◽  
Author(s):  
Nicole VERZIJL ◽  
Jeroen DEGROOT ◽  
Esther OLDEHINKEL ◽  
Ruud A. BANK ◽  
Suzanne R. THORPE ◽  
...  

1978 ◽  
Vol 176 (3) ◽  
pp. 683-693 ◽  
Author(s):  
M T Bayliss ◽  
S Y Ali

1. Analysis of the purified proteoglycans extracted from normal human articular cartilage with 4M-guanidinium chloride showed that there was an age-related increase in their content of protein and keratan sulphate. 2. The hydrodynamic size of the dissociated proteoglycans also decreased with advancing age, but there was little change in the proportion that could aggregate. 3. Results suggested that some extracts of aged-human cartilage had an increased content of hyaluronic acid compared with specimens from younger patients. 4. Dissociated proteoglycans, from cartilage of all age groups, bind to hyaluronic acid and form aggregates in direct proportion to the hyaluronic acid concentration. 5. Electrophoretic heterogeneity of the dissociated proteoglycans was demonstrated on polyacrylamide/agarose gels. The number of proteoglycan species observed was also dependent on the age of the patient.


1969 ◽  
Vol 114 (4) ◽  
pp. 673-678 ◽  
Author(s):  
O. Snellman

Cathepsin B from calf liver was obtained by a method involving preparation of a lysosomal–mitochondrial pellet and treatment of this pellet with acetone. The material was extracted with an acid buffer, pH4·0, and then precipitated from the extract with acetone. The precipitate was dissolved in phosphate buffer, pH7·4, and subjected to gel filtration on Sephadex G-200 and G-100. The cathepsin B emerged in a range of molecular weight much lower than 50000 as a well-defined component. The purity of this material was checked by electrophoresis. To obtain maximum activity the enzyme had to be activated with a chelating agent and a reducing agent (i.e. EDTA and cysteine). A number of different substrates were used. The enzyme was active for the hydrolysis of both peptide bonds and ester bonds and had approximately equal reactivity in the two cases. The pH-dependence of the hydrolysis was the same with both substrates. The binding of the substrates was half-maximal at pH4·5 and at pH6·8. A thiol group occurred in the active centre but this group ought to have a much higher pK than that found in this enzyme.


1973 ◽  
Vol 52 (3) ◽  
pp. 624-633 ◽  
Author(s):  
Asher I. Sapolsky ◽  
Roy D. Altman ◽  
J. Frederick Woessner ◽  
David S. Howell

1979 ◽  
Vol 59 (1) ◽  
pp. 167-179 ◽  
Author(s):  
T. NAKANO ◽  
F. X. AHERNE ◽  
J. R. THOMPSON

Twenty-five crossbred boars reared under normal conditions were serially slaughtered at the age of 3 days, and 5, 10, 20 and 30 wk. Five boars were slaughtered at each age and morphological, histochemical and biochemical age-related changes in femoral condylar articular cartilage were studied. No osteochondrotic joints were found in pigs 10 wk of age or younger, while 7 of the 10 boars slaughtered at 20 and 30 wk of age were osteochondrotic. Cartilage thickness increased (P < 0.05) until the age of 5 wk and decreased (P < 0.05) thereafter. Cell density decreased (P < 0.05) as age advanced. Age-associated changes found in the chemical composition of the cartilage were an increase in the concentration of dry matter and hydroxyproline and a decrease in the concentration of glycosaminoglycans (GAG) including chondroitin sulfate (ChS), keratan sulfate and hyaluronic acid. The proportions of soluble proteoglycan and 4-sulfated disaccharide from the ChS fraction decreased (P < 0.05) while the proportion of 6-sulfated disaccharide from ChS increased (P < 0.05). Osteochondrosis was observed as a disturbed endochondral ossification, and softening and fracture of the cartilage. The former was accompanied by a loss of intercellular GAG and cell necrosis, and the latter by local losses of GAG and cells. Osteochondrotic cartilage also contained higher proportions of soluble proteoglycan and 6-sulfated disaccharide, and lower proportions of 4-sulfated disaccharide than did the visually normal cartilage.


1982 ◽  
Vol 2 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Brian R. Champion ◽  
Agnes Reiner ◽  
Peter J. Roughley ◽  
A. Robin Poole

1988 ◽  
Vol 250 (2) ◽  
pp. 435-441 ◽  
Author(s):  
M W A Holmes ◽  
M T Bayliss ◽  
H Muir

Total tissue content and molecular mass of hyaluronic acid was determined in papain digests of human articular cartilage using a sensitive radiosorbent assay [Laurent & Tengblad (1980) Anal. Biochem. 109, 386-394]. 1) Hyaluronic acid content increased from 0.5 microgram/mg wet wt. to 2.5 micrograms/mg wet wt. between the ages of 2.5 years and 86 years. 2) Hyaluronic acid chain size decreased from Mr 2.0 x 10(6) to 3.0 x 10(5) over the same age range. 3) There was no age-related change in the size of newly-synthesized hyaluronic acid, which was of very high molecular mass, in both immature and mature cartilage. The results are consistent with an age-related decrease in proteoglycan aggregate size and suggest that modification of the hyaluronic acid chain may take place in the extracellular matrix.


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