scholarly journals Characterization of cathepsins in cartilage

1967 ◽  
Vol 105 (2) ◽  
pp. 549-557 ◽  
Author(s):  
S. Y. Ali ◽  
L. Evans ◽  
E. Stainthorpe ◽  
C. H. Lack
Keyword(s):  
Cathepsin B ◽  
Cartilage Matrix ◽  
Heat Inactivation ◽  
Ph Values ◽  
Fixed Weight ◽  
Exogenous Substrate ◽  
Nitrophenyl Phosphate ◽  
Rabbit Ear ◽  
Ear Cartilage

The presence of a cathepsin B-like enzyme in rabbit ear cartilage was established by the use of the synthetic substrates benzoyl-l-arginine amide and benzoyl-dl-arginine 2-naphthylamide. This was facilitated by using a technique that permits the incubation of a fixed weight of thin (18μ) cartilage sections with an appropriate exogenous substrate. The enzymic properties of cathepsin B in cartilage have been compared with an endogenous enzyme that liberates chondromucopeptide by degrading the cartilage matrix autocatalytically at pH5. Besides being maximally active at pH4·7, these cartilage enzymes are enhanced in activity by cysteine and inhibited by arginine analogues, iodoacetamide, chloroquine and mercuric chloride. They are not inhibited by EDTA, di-isopropyl phosphorofluoridate and diethyl p-nitrophenyl phosphate. When inhibiting the release of chondromucopeptide from cartilage at pH5, the arginine-containing synthetic substrates are hydrolysed simultaneously. These enzymes also share the same heat-inactivation characteristics at various pH values, being stable at acid pH and unstable at neutral and alkaline pH. The experimental evidence indicates that a cathepsin B-like enzyme may be partly responsible for the autolytic degradation of cartilage matrix at pH5.

scholarly journals Studies on the cathepsins in elastic cartilage

1969 ◽  
Vol 112 (4) ◽  
pp. 427-433 ◽  
Author(s):  
S. Y. Ali ◽  
Lois Evans
Keyword(s):  
Acid Phosphatase ◽  
Dna Content ◽  
Quantitative Method ◽  
Cathepsin C ◽  
Elastic Cartilage ◽  
Fixed Weight ◽  
Cathepsin Activity ◽  
Rabbit Ear ◽  
Ear Cartilage ◽  
Hydrolysis Of

1. The presence of several enzymes in rabbit ear cartilage was examined by a quantitative method that permits the incubation of a fixed weight of cartilage sections (18μm.) with an appropriate exogeneous substrate. 2. As the presence of cathepsins B and D in cartilage has already been established, evidence is now provided to show that cathepsins A and C are also present and are maximally active at pH5. 3. Cathepsin A was recognized by its hydrolysis of benzyloxycarbonyl-glutamyl-tyrosine and cathepsin C by its hydrolysis of glycyl-tyrosine amide; the cartilage also hydrolysed benzyloxycarbonyl-glutamyl-phenylalanine and benzoyl-dl-phenylalanine 2-naphthyl ester at pH5. 4. The acid phosphatase activity and the DNA content of cartilage have also been measured to provide a basis for comparison with the cathepsin activity of cartilage obtained from other sites and species.

scholarly journals Proteoglycan-degrading enzymes. A radiochemical assay method and the detection of a new enzyme cathepsin F

1977 ◽  
Vol 167 (3) ◽  
pp. 775-785 ◽  
Author(s):  
J T Dingle ◽  
A M J Blow ◽  
A J Barrett ◽  
P E N Martin
Keyword(s):  
Enzyme Concentration ◽  
Assay Method ◽  
Human Articular Cartilage ◽  
Ph Values ◽  
Degrading Enzymes ◽  
Incubation Experiments ◽  
Rabbit Ear ◽  
Ear Cartilage ◽  
Cathepsin F ◽  
Made In

1. Polyacrylamide beads containing entrapped 35S-labelled proteoglycan molecules have been prepared. 2. The measurement of release of radioactivity provides an extremely sensitive assay for proteoglycan-degrading enzymes, including proteinases and hyaluronidase. 3. The amount of label released is a logarithmic function of enzyme concentration or time of incubation. Experiments were made in an attempt to explain this. 4. Assays were made by the new method at several pH values, and with the inclusion of inhibitors to identify the proteoglycan-degrading enzymes of rabbit ear cartilage. 5. A previously undescribed proteinase active against proteoglycan at pH4.5 but unaffected by pepstatin, was discovered. The enzyme was named cathepsin F, and was partially purified and characterized; it was detected in human articular cartilage.

Mn-Mo-O Catalysts for Methanol Oxidation. I. Preparation and Characterization of the Catalysts

1992 ◽  
Vol 57 (12) ◽  
pp. 2529-2538 ◽  
Author(s):  
Krasimir Ivanov ◽  
Penka Litcheva ◽  
Dimitar Klissurski
Keyword(s):  
Methanol Oxidation ◽  
Solution Concentration ◽  
Alkaline Media ◽  
Acidic Media ◽  
Chemical Methods ◽  
X Ray ◽  
Ph Values ◽  
Precipitate Composition

Mn-Mo-O catalysts with a different Mo/Mn ratio have been prepared by precipitation. The precipitate composition as a function of solution concentration and pH was studied by X-ray, IR, thermal and chemical methods. Formation of manganese molybdates with MnMoO4.1.5H2O, Mn3Mo3O12.2.5H2O, and Mn3Mo4O15.4H2O composition has been supposed. It is concluded that pure MnMoO4 may be obtained in both acid and alkaline media, the pH values depending on the concentration of the initial solutions. The maximum Mo/Mn ratio in the precipitates is 1.33. The formation of pure Mn3Mo4O15.4H2O is possible in weakly acidic media. This process is favoured by increasing the concentration of initial solutions.

Purification and partial amino acid sequence of thuricin S, a new anti-Listeriabacteriocin from Bacillus thuringiensis

2007 ◽  
Vol 53 (2) ◽  
pp. 284-290 ◽  
Author(s):  
Sonia Chehimi ◽  
François Delalande ◽  
Sophie Sablé ◽  
Mohamed-Rabeh Hajlaoui ◽  
Alain Van Dorsselaer ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Proteinase K ◽  
Terminal Sequence ◽  
Partial Amino Acid Sequence ◽  
Ph Values ◽  
Heat Stable ◽  
Isolation And Characterization ◽  
Terminal Amino ◽  
Edman Sequencing

We report the isolation and characterization of a new bacteriocin, thuricin S, produced by the Bacillus thuringiensis subsp. entomocidus HD198 strain. This antibacterial activity is sensitive to proteinase K, is heat-stable, and is stable at a variety of pH values (3–10.5). The monoisotopic mass of thuricin S purified by high perfomance liquid chromatography, as determined with mass spectrometry ESI-TOF-MS, is 3137.61 Da. Edman sequencing and NanoESI-MS/MS experiments provided the sequence of the 18 N-terminal amino acids. Interestingly, thuricin S has the same N-terminal sequence (DWTXWSXL) as bacthuricin F4 and thuricin 17, produced by B. thuringiensis strains BUPM4 and NEB17, respectively, and could therefore be classified as a new subclass IId bacteriocin.

scholarly journals Phosphatase synthesis in Klebsiella (Aerobacter) aerogenes growing in continuous culture

1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Continuous Culture ◽  
Activity Profile ◽  
Glucose Effect ◽  
Ph Values ◽  
Nitrophenyl Phosphate ◽  
Wide Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.

Characterization of the cathepsin B-like proteinases of Trichomonas tenax ATCC 30207

2000 ◽  
Vol 15 (6) ◽  
pp. 360-364 ◽  
Author(s):  
A. Yamamoto ◽  
E. Asaga ◽  
E. Nagao ◽  
T. Igarashi ◽  
N. Goto
Keyword(s):  
Cathepsin B

scholarly journals Characterization of Melanoidins and Color Development in Dulce de Leche, a Confectionary Dairy Product With High Sucrose Content: Evaluation of pH Effect, an Essential Manufacturing Process Parameter

2021 ◽  
Vol 8 ◽  
Author(s):  
Analía Rodríguez ◽  
Patricia Lema ◽  
María Inés Bessio ◽  
Guillermo Moyna ◽  
Cristina Olivaro ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ph Effect ◽  
Dairy Product ◽  
Gel Filtration ◽  
Significant Degree ◽  
Product Analysis ◽  
Molecular Weights ◽  
Ph Values ◽  
Initial Ph

The effect on color of the initial pH employed in dulce de leche (DL) production was evaluated through physicochemical and spectroscopical characterization of the melanoidins formed in the process. Melanoidins originated at pH values of 6.5, 7.0, and 7.5, and they were released by the enzymatic hydrolysis of the protein backbone and purified by gel filtration. They showed a significant degree of polydispersity, in general, with molecular weights (MWs) below 1,800 Da. DL produced at a higher pH released melanoidins with higher average MW after the enzymatic hydrolysis. They also presented darker colors (dE*ab, C*), more closely resembling those typical of the commercial product. Analysis of the fractions isolated by gel filtration using HPLC-DAD and multinuclear NMR showed an heterogeneous and complex composition. Even though structurally related, the 1H NMR spectra of melanoidins showed a higher degree of aromaticity at higher pH values. In conclusion, the pH employed in DL production affects the amount and structure of the colored products originated by MR reactions, and thus the color of the final product.

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