Inhibition of bovine cathepsin B by amino acid-derived nitriles

1990 ◽  
Vol 18 (2) ◽  
pp. 316-316 ◽  
Author(s):  
PAULA P. PICKEN ◽  
DAVID J. S. GUTHRIE ◽  
BRIAN WALKER
Keyword(s):  
Amino Acid ◽  
Cathepsin B

scholarly journals E64 [trans-epoxysuccinyl-l-leucylamido-(4-guanidino)butane] analogues as inhibitors of cysteine proteinases: investigation of S2 subsite interactions

1994 ◽  
Vol 299 (2) ◽  
pp. 389-392 ◽  
Author(s):  
B J Gour-Salin ◽  
P Lachance ◽  
M C Magny ◽  
C Plouffe ◽  
R Ménard ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cathepsin B ◽  
Benzyl Ester ◽  
Amide Proton ◽  
Side Chain ◽  
Cysteine Proteinases ◽  
Enzyme Substrate ◽  
Amide Derivatives ◽  
Benzyl Esters ◽  
S2 Subsite

A number of epoxysuccinyl amino acid benzyl esters (HO-Eps-AA-OBzl) and benzyl amides (HO-Eps-AA-NHBzl) (where AA represents amino acid) were synthesized as analogues of E64, a naturally occurring inhibitor of cysteine proteinases. These inhibitors were designed to evaluate if selectivity for cathepsin B could be achieved by varying the amino acid on the basis of known substrate specificity. Contrary to the situation with substrates, it was found that variation of the amino acid in the E64 analogues does not lead to major changes in the kinetic parameter kinac./Ki and that the specificity of these analogues does not parallel that observed for substrates. This is particularly true in the case of the benzyl ester derivatives where the deviation from substrate-like behaviour is more important than with the benzyl amide derivatives. The results suggest that the amide proton of the benzyl amide group in HO-Eps-AA-NHBzl interacts in the S2 subsite in both cathepsin B and papain and contributes to increase the potency of these inhibitors. The kinetic data also suggest that differences in the orientation of the C alpha-C beta bond of the side chain in the S2 subsite of the enzyme might explain the differences between substrate and E64 analogue specificities. This hypothesis is supported by the fact that the order of inactivation rates with chloromethane inhibitors (which are believed to be good models of enzyme-substrate interactions) is indeed very similar to that observed with the corresponding amidomethylcoumarin substrates. In conclusion, the information available from S2-P2 interactions with substrates cannot be used to enhance the selectivity of the E64 analogues in a rational manner.

scholarly journals Extracellular-matrix degradation at acid pH. Avian osteoclast acid collagenase isolation and characterization

1993 ◽  
Vol 290 (3) ◽  
pp. 873-884 ◽  
Author(s):  
H C Blair ◽  
S L Teitelbaum ◽  
L E Grosso ◽  
D L Lacey ◽  
H L Tan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Substrate Specificity ◽  
Cathepsin B ◽  
Type I Collagen ◽  
Sequence Similarity ◽  
Bone Matrix ◽  
Collagenolytic Activity ◽  
Type I ◽  
Isolation And Characterization

Osteoclasts degrade bone matrix, which is mainly type I collagen and hydroxyapatite, in an acidic extracellular compartment. Thus we reasoned that osteoclasts must produce an acid collagenase. We purified this enzyme, a 31 kDa protein, from avian osteoclast lysates (in 100 mM acetate/1 mM CHAPS/1 mM dithiothreitol, pH 4.4), fractionated by (NH2)2SO4 precipitation, gelatin-affinity, cation exchange, and gel filtration. Fraction activity was measured using diazotized collagen or 3H-labelled cross-linked collagen (decalcified and trypsin-treated metabolically L-[4,5-3H]proline-labelled bone) as substrates. Iodoacetate, leupeptin, antipain, pepstatin and mercurials inhibited collagenolysis by the isolated proteinase; mercurial derivatives could not be re-activated by dithiothreitol. Collagen degradation was maximal at pH 4.4; purified proteinase reproduced the collagenolytic activity of cell lysates. The N-terminal amino acid sequence from the isolated protein and its CNBr degradation fragments showed sequence similarity to mammalian cathepsin Bs, and near-identity with avian liver cathepsin B. Peptide substrate specificity of the osteoclastic enzyme resembled those of mammalian cathepsin B and its avian liver counterpart, but degradation of low-molecular-mass substrates by the osteoclastic enzyme was slower, reflecting generally lower kcat. values. Further, kcat/Km varied less between arginine-containing substrates than for previously reported cathepsin Bs, indicating different substrate specificity of the osteoclast enzyme. Polyclonal antibody raised to a 25 kDa fragment of the enzyme recognized a single 31 kDa band in SDS/PAGE of osteoclast lysates blotted to poly(vinylidene difluoride), adsorbed collagenolytic activity of osteoclast lysates, and stained avian osteoclasts in tissue sections. Degenerate sense- and antisense-oligonucleotide primers, predicted from segments of primary amino acid sequence, amplified a 486 bp DNA fragment; this was cloned and sequenced. Of 162 amino acids encoded, 77% are identical with those of human cathepsin B; hybridization identified a 2.4 kb RNA in osteoclast lysates. We conclude that the major avian osteoclast collagenolytic enzyme is a cathepsin B, whose activity varies from other enzymes of its class.

N-Haloacetyl-amino-acid amides as active-site-directed inhibitors of papain and cathepsin B

1992 ◽  
Vol 27 (9) ◽  
pp. 865-873 ◽  
Author(s):  
C Giordano ◽  
C Gallina ◽  
V Ottaviano ◽  
V Consalvi ◽  
R Scandurra
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Cathepsin B

scholarly journals Action of human liver cathepsin B on the oxidized insulin B chain

1983 ◽  
Vol 213 (2) ◽  
pp. 467-471 ◽  
Author(s):  
M J McKay ◽  
M K Offermann ◽  
A J Barrett ◽  
J S Bond
Keyword(s):  
Amino Acid ◽  
Cathepsin B ◽  
Human Liver ◽  
Degradation Products ◽  
Cysteine Proteinase ◽  
Cathepsin L ◽  
Amino Acid Content ◽  
Peptide Bond ◽  
Cleavage Sites ◽  
Amino Acid Residues

The lysosomal cysteine proteinase cathepsin B (from human liver) was tested for its peptide-bond specificity against the oxidized B-chain of insulin. Sixteen peptide degradation products were separated by high-pressure liquid chromatography and thin-layer chromatography and were analysed for their amino acid content and N-terminal amino acid residue. Five major and six minor cleavage sites were identified; the major cleavage sites were Gln(4)-His(5), Ser(9)-His(10), Glu(13)-Ala(14), Tyr(16)-Leu(17) and Gly(23)-Phe(24). The findings indicate that human cathepsin B has a broad specificity, with no clearly defined requirement for any particular amino acid residues in the vicinity of the cleavage sites. The enzyme did not display peptidyldipeptidase activity with this substrate, and showed a specificity different from those reported for two other cysteine proteinases, papain and rat cathepsin L.

scholarly journals Amino Acid Concentrations and Protein Metabolism of Two Types of Rat Skeletal Muscle in Postprandial State and After Brief Starvation

2017 ◽  
pp. 959-967 ◽  
Author(s):  
M. HOLEČEK ◽  
S. MIČUDA
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Metabolism ◽  
Cathepsin B ◽  
Fed State ◽  
Postprandial State ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Amino Acid Concentrations

We have investigated amino acid concentrations and protein metabolism in musculus extensor digitorum longus (EDL, fast-twitch, white muscle) and musculus soleus (SOL, slow-twitch, red muscle) of rats sacrificed in the fed state or after one day of starvation. Fractional protein synthesis rates (FRPS) were measured using the flooding dose method (L-[3,4,5-3H]phenylalanine). Activities of two major proteolytic systems in muscle (the ubiquitin-proteasome and lysosomal) were examined by measurement of chymotrypsin like activity of proteasome (CTLA), expression of ubiquitin ligases atrogin-1 and muscle-ring-finger-1 (MuRF-1), and cathepsin B and L activities. Intramuscular concentrations of the most of non-essential amino acids, FRPS, CTLA and cathepsin B and L activities were in postprandial state higher in SOL when compared with EDL. The differences in atrogin-1 and MuRF-1 expression were insignificant. Starvation decreased concentrations of a number of amino acids and increased concentrations of valine, leucine, and isoleucine in blood plasma. Starvation also decreased intramuscular concentrations of a number of amino acids differently in EDL and SOL, decreased protein synthesis (by 31 % in SOL and 47 % in EDL), and increased expression of atrogin-1 and MuRF-1 in EDL. The effect of starvation on CTLA and cathepsin B and L activities was insignificant. It is concluded that slow-twitch (red) muscles have higher rates of protein turnover and may adapt better to brief starvation when compared to fast-twitch (white) muscles. This phenomenon may play a role in more pronounced atrophy of white muscles in aging and muscle wasting disorders.

scholarly journals Fluorogenic peptide substrates for carboxydipeptidase activity of cathepsin B.

2004 ◽  
Vol 51 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Krystyna Stachowiak ◽  
Monika Tokmina ◽  
Anna Karpińska ◽  
Renata Sosnowska ◽  
Wiesław Wiczk
Keyword(s):  
Amino Acid ◽  
Cysteine Protease ◽  
Cathepsin B ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Kinetic Studies ◽  
Amino Acid Sequences ◽  
Peptide Substrates ◽  
Donor And Acceptor ◽  
Specificity Constant

Cathepsin B is a lysosomal cysteine protease exhibiting mainly dipeptidyl carboxypeptidase activity, which decreases dramatically above pH 5.5, when the enzyme starts acting as an endopeptidase. Since the common cathepsin B assays are performed at pH 6 and do not distinguish between these activities, we synthesized a series of peptide substrates specifically designed for the carboxydipeptidase activity of cathepsin B. The amino-acid sequences of the P(5)-P(1) part of these substrates were based on the binding fragments of cystatin C and cystatin SA, the natural reversible inhibitors of papain-like cysteine protease. The sequences of the P'(1)-P'(2) dipeptide fragments of the substrates were chosen on the basis of the specificity of the S'(1)-S'(2) sites of the cathepsin B catalytic cleft. The rates of hydrolysis by cathepsin B and papain, the archetypal cysteine protease, were monitored by a continuous fluorescence assay based on internal resonance energy transfer from an Edans to a Dabcyl group. The fluorescence energy donor and acceptor were attached to the C- and the N-terminal amino-acid residues, respectively. The kinetics of hydrolysis followed the Michaelis-Menten model. Out of all the examined peptides Dabcyl-R-L-V-G-F- E(Edans) turned out to be a very good substrate for both papain and cathepsin B at both pH 6 and pH 5. The replacement of Glu by Asp turned this peptide into an exclusive substrate for cathepsin B not hydrolyzed by papain. The substitution of Phe by Nal in the original substrate caused an increase of the specificity constant for cathepsin B at pH 5, and a significant decrease at pH 6. The results of kinetic studies also suggest that Arg in position P(4) is not important for the exopeptidase activity of cathepsin B, and that introducing Glu in place of Val in position P(2) causes an increase of the substrate preference towards this activity.

Amino acid sequence of human liver cathepsin B

FEBS Letters ◽  
1985 ◽  
Vol 181 (1) ◽  
pp. 169-172 ◽  
Author(s):  
Anka Ritonja ◽  
Tatjana Popovic ◽  
Vito Turk ◽  
Karin Wiedenmann ◽  
Werner Machleidt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cathepsin B ◽  
Human Liver
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