[Can a protein data bank help to define the binding site of proteolytic enzyme?].
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
B Keil
Publications and source records attributed to B Keil.
Specificity of the collagenase from the insect Hypoderma lineatum.
Specificity of the collagenase from the larvae Hypoderma lineatum, a serine protease related to trypsin, has been investigated by using native collagen and non-collagenous substrates. At 25 degrees C and neutral pH the degradation of collagen by the larval enzyme in solution results in a 52% loss of specific viscosity, without loss of helicity. Electron microscopy of segment-long-spacing crystallites of the digest shows the occurrence of one cleavage region between bands 41 and 44 whereas Edman degradation indicates several cleavage loci in this region. Hypoderma collagenase differs from proteinases I and II from the crab Uca pugilator, which catalyse cleavages in multiple regions of the collagen molecule, and also from vertebrate collagenases, which cleave collagen only between residues 775 and 776. Apart of specific action on collagen, Hypoderma collagenase degrades the oxidized chain B of insulin; the major cleavage occurs at the Leu15-Tyr16 bond followed by two minor cleavages at the Arg22-Gly23 and Lys29-Ala30 bonds. The larval enzyme has no action on synthetic peptide substrates of trypsin or chymotrypsin.
Amino Acid Sequence↗
Collagenase in mineralized tissues of human teeth.
A collagenase cleaving native type I [14C]collagen but inactive against the synthetic substrate Pz-Pro-Leu-Gly-Pro-D-Arg was extracted from mineralized human dental tissue. The enzyme specifically degrades native collagen into characteristic products (3/4) and (1/4). Its apparent molecular mass of 68 kDa is relatively high in comparison with collagenases from other oral tissues. The enzyme is a metalloproteinase inhibited by low concentrations of the chelating agents EDTA, 1, 10-phenanthroline, alpha alpha'-dipyridyl, and not affected by diisopropylfluorophosphate, soybean trypsin inhibitor, and p-chloromercuribenzoate. It is stable to lyophilization and can be stored at-20 degrees C for at least 6 months.
2,2'-Dipyridyl↗
Primary structure of alpha-clostripain light chain.
The primary structure of light chain of alpha-clostripain was determined by sequence analysis of peptides derived from tryptic digests purified by reverse-phase high-performance liquid chromatography. The 22 isolated tryptic peptides were aligned by peptides derived from chymotryptic and staphylococcal V8 proteinase digests. The light chain contains 133 amino acids residues and has a relative molecular mass of 15400. The prediction of its secondary structure is given.
Amino Acid Sequence↗
Evidence for an active-center cysteine in the SH-proteinase alpha-clostripain through use of N-tosyl-L-lysine chloromethyl ketone.
The rapid reaction of alpha-clostripain with tosyl-L-lysine chloromethyl ketone results in a complete loss of activity and in the disappearance of one titratable SH group whereas the number of histidine residues is not affected. Tosyl-L-phenylalanine chloromethyl ketone and phenylmethylsulfonyl fluoride have no effect on the catalytic activity. From the molar ratio and under the assumption of 1:1 molar interaction, the fully active enzyme has a specific activity of 650-700 units/mg [twice the value proposed by Porter et al. (J. Biol. Chem. 246 (1971) 7675-7682)]. Partial oxidation makes it experimentally impossible to attain this maximal value.
Alkylating Agents↗
Hypodermin B, a trypsin-related enzyme from the insect Hypoderma lineatum. Comparison with hypodermin A and Hypoderma collagenase, two serine proteinases from the same source.
Hypodermin B, a serine proteinase with a molecular weight of 23000, was purified to homogeneity from the larvae Hypoderma lineatum. It is stoichiometrically inhibited by diisopropylfluorophosphate and fully inactivated by N-tosyllysine chloromethyl ketone and soya bean and bovine pancreatic trypsin inhibitors. N-Tosylphenylalanine chloromethyl ketone and ovomucoid are without effect on its activity. Hypodermin B hydrolyses both amide and ester substrates of trypsin but does not display any chymotryptic activity on synthetic substrates. Its specificity on the B chain of insulin is slightly broader than that of bovine trypsin. Its amino acid composition and N-terminal sequence suggest structural homology with serine proteinases of the trypsin family and with two other serine proteinases, hypodermin A and Hypoderma collagenase, previously isolated from the same larvae. Hypodermins A and B are very similar with respect to their inhibition and specificity, they differ however strongly from Hypoderma collagenase.
Amino Acid Sequence↗
Structural study on the active site of the collagenase from Hypoderma lineatum.
The collagenase from the larvae Hypoderma lineatum is a serine proteinase sequentially related to the trypsin family. The tryptic peptide containing the serine residue of the active site, labelled with [3H] diisopropylfluorophosphate was isolated and determined to be Ser-Pro-Cys-Phe-Gly-Asp-Ser-Gly-Gly-Pro-(Phe-Ser)-Lys. It is highly conservative with respect to the corresponding peptide in other serine proteinases related to trypsin.
Animals↗
Amino-acid sequences of the active-site sulfhydryl peptide and other thiol peptides from the cysteine proteinase alpha-clostripain.
One free -SH group in the heavy chain of alpha-clostripain reacts rapidly with N-tosyllysine chloromethyl ketone which inactivates the enzyme. Iodoacetic acid also reacts with the thiol group required for enzyme activity but more slowly. A tryptic peptide containing the reactive sulfhydryl group labelled with iodo[1-14C]acetic acid was isolated and determined to be Gln-Ser-Val-Asp-Leu-Leu-Ala-Phe-Asp-Ala-Cys-Met. All other cysteine peptides were isolated from the trypsin hydrolysate of the [14C]carboxymethylated enzyme. Moreover N-terminal and C-terminal sequences of both chains of alpha-clostripain were determined. The sequences representing 20% of the primary structure of alpha-clostripain are not homologous with either other cysteine proteinases or with any other protein structure known to date.
Amino Acid Sequence↗
Cell-surface collagen-binding protein in the procaryote Achromobacter iophagus.
Collagen and its high-molecular-weight fragments specifically induce an extracellular collagenase (EC 3.4.24.8) in the Gram-negative Achromobacter iophagus. During the induction process the inducer is concentrated on the bacterial outer membrane. Two-dimensional electrophoresis of 125I-labelled outer membrane proteins has shown that, in particular, the amount of one protein which is already present on the surface of non-induced bacteria increases quantitatively when the inducer is added. After 125I-labelling of the cell membrane and its solubilization, the same protein is retained selectively on a gelatin-Sepharose column. It has isoelectric point of 4.9-5.1 and molecular weight of 40000. This molecular weight is close to that of the 35000 of the collagenase subunit. However, their non-identity was proved in three independent ways: upon two-dimensional electrophoresis, only those proteins in the range corresponding to the collagenase dimer (Mr 70000-80000) react with fluorescent anticollagenase antibody system, whereas the spot of the collagen-binding protein (mr 40000) is negative; the solubilized collagen-binding protein is not retained by anticollagenase-Sepharose affinity chromatography; in vivo, it is not protected by anti-collagenase antibodies against lactoperoxidase iodination. A hypothesis for the possible role of the collagen-binding protein in the induction of collagenase is proposed.
Alcaligenes↗
Crystallization and preliminary x-ray diffraction data for the collagenase of Hypoderma lineatum larvae.
Explore the source record for details and available documents.
Animals↗
Chemical characterization of the homogeneous collagenase from Clostridium histolyticum.
Pure collagenase (clostridiopeptidase A, EC 3.4.24.3) having a molecular weight of 70 000 was obtained from the culture medium of Clostridium histolyticym by a combination of ultrafiltrations, molecular sieve, affinity and hydrophobic chromatography. The value of its specific activity is the highest of those described previously but 6-times lower than that of the collagenase from Achromobacter iophagus (EC 3.4.24.8). Its amino acid composition differs from previous data, namely by the presence of cysteine, methionine, tryptophan and O-phosphoserine residues. In contrast to Achromobacter collagenase it does not dissociate in subunits during the deactivation by EDTA or LiCl/glycine buffer at pH 10.5. Existence of multiple forms of Clostridium collagenase previously described is discussed as being due to autolysis of a single molecular species or to a different degree of phosphorylation.
Alcaligenes↗
The isolation and characterization of a concanavalin A receptor from boar spermatozoa surface.
Boar spermatozoa were radioactively labeled by either lactoperoxidase-catalysed iodination or galactose oxidase oxidation followed by reduction with tritiated sodium borohydride. Plasma membrane glycoproteins were solubilized with the non-ionic detergent Nonidet P40 and separated by affinity chromatography on concanavalin A-Sepharose. A major water-soluble concanavalin A receptor of molecular weight greater than 160 000 was isolated by gel filtration and ion-exchange chromatography. Its amino acid and carbohydrate composition were determined. This glycoprotein is susceptible to digestion by trypsin or chymotrypsin.
Amino Acids↗
Hypodermin A, a trypsin-like neutral proteinase from the insect Hypoderma lineatum.
Hypodermin A, a serine proteinase from the larva Hypoderma lineatum, with a molecular weight of 27 000 was obtained in pure form by ion-exchange chromatography. It is inhibited by diisopropyl phosphofluorate, a serine proteinase inhibitor, but not by metallo or cysteine enzyme inhibitors such as EDTA or thiol reagents. In the same way, it is fully inactivated by trypsin inhibitors, but not by specific chymotrypsin inhibitors. Its specificity, limited to carboxyl side of arginine residue in B-chain of insulin, is more complicated on other polypeptide substrates. Sequence analysis suggests structural homology with H. lineatum collagenase as well as with other members of the trypsin family.
Amino Acid Sequence↗
Circular dichroism comparative studies of two bacterial collagenases and thermolysin.
The recently isolated and purified collagenase produced by Achromobacter iophagus, the collagenase from Clostridium histolyticum, and thermolysin, three enzymes having common properties, were studied by circular dichroism. From the spectra of the aqueous solutions obtained in the peptide region, the fraction of alpha helix, beta sheet and aperiodic segments in the three proteins could be estimated. Good similarity was found between Achromobacter collagenase and thermolysin, which both contain a high fraction of alpha helix. Side-chain contributions were analyzed in the aromatic region of thespectra: effects of pH and of organic solvents were observed, showing the strong influence of surroundings on the stabilization of the proteins.
Alcaligenes↗
Sequential homology of the collagenase from eucaryote Hypoderma lineatum with the proteinases of the trypsin family.
Explore the source record for details and available documents.
Amino Acid Sequence↗
A comparison of surface proteins in embryonal carcinoma cells and their differentiated derivatives.
Surface proteins from five cell lines (three embryonal carcinoma cell lines (F9, PCC4 and PCC3), teratocarcinoma-derived endodermal cells (PYS) and fibroblasts (line 3/A/1-D-3 differentiated from PCC3) were compared by two-dimensional polyacrylamide gel electrophoresis after selective iodination with 125I in the presence of lactoperoxidase. The labeled proteins were solubilized either in Nonidet P40/urea/ampholyte/mercaptoethanol solution or in Nonidet P40 only. In total, about thirty major 125I-labeled surface proteins were identified by their isoelectric point and molecular weight. 14 proteins are present in all five cell types, although their quantity or accessibility for labeling differs between differentiated and undifferentiated cells. Three proteins (200, 160 and 150 kilodaltons) are present in undifferentiated cells only. Two of them (160 and 150 kilodaltons) were solubilized by Nonidet P40/urea/ampholyte/mercaptoethanol, but not by Nonidet P40. One protein (50 kilodaltons) was found in nullipotent F9 cells only. About 14--15 proteins (including fibronectin) were released by Nonidet P40/urea/ampholyte/mercaptoethanol but not by Nonidet P40. They are presumably bound to submembrane or cytoskeleton structures by non-covalent bonds.
Animals↗
Chemical modifications of Achromobacter collagenase and their influence on the enzymic activity.
A study of the influence of chemical modifications on the activity of Achromobacter iophagus collagenase (EC 3.4.24.8) has led to the following conclusions: a modification of 4 out of 80 COOH groups with carbodiimide led to 90% loss of enzymic activity. A 70% inactivation was found after modification of two tyrosines out of 30 with tetranitromethane. The modification of four to six tryptophans out of 16 with 2-hydroxy-5-nitrobenzyl bromide decreased enzyme activity to 36%. This inactivation is accelerated in the presence of collagen. An increase of reagent/enzyme molar ratio led to a modification of 16 tryptophan residues and denaturation of Acahromobacter collagenase. A modification of two arginines out of 18 with 1,2-cyclohexanedione and eight NH2 groups out of 24 with 2,3-dimethyl maleic anhydride does not change the collagenolytic activity. All NH2 groups become available for 2,3-dimethyl maleic anhydride after dissociation of the dimer. A possible analogy of hydrolytic site of collagenase with that of two other known bacterial metalloproteinases (thermolysin and Bacillus subtilis neutral proteinase (EC 3.4.24.4)) is discussed.
2-Hydroxy-5-nitrobenzyl Bromide↗
Differences in the degradation of native collagen by two microbial collagenases.
The early stages of degradation of native collagen by two bacterial collagenases were studied by electron microscopy and by automatic Edman degradation. The purified collagenase from Clostridium histolyticum was shown to cleave native collagen at several sites, but not progressively from the N-terminus, as had been previously suggested. The homogeneous collagenase from Achromobacter iophagus cleaves native collagen preferentially at two sites corresponding to the interbands 33-34 and 41-42. The latter lies within the region cleaved by the eukaryotic collagenases.
Alcaligenes↗