Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

'pH-jump' crystallographic analyses of gamma-lactam-porcine pancreatic elastase complexes.

ABSTRACT: beta-Lactams inhibit a range of enzymes via acylation of nucleophilic serine residues. Certain gamma-lactam analogues of monocyclic beta-lactams have also been shown to be reversible inhibitors of porcine pancreatic elastase (PPE), forming acyl-enzyme complexes that are stable with respect to hydrolysis. Crystallographic analysis at pH 5 of an acyl-enzyme complex formed with PPE and one of these inhibitors revealed the ester carbonyl located in the oxyanion hole in a similar conformation to that observed in the structure of a complex formed between a heptapeptide (beta-casomorphin-7) and PPE. Only weak electron density was observed for the His-57 side chain in its 'native' conformation. Instead, the His-57 side chain predominantly adopted a conformation rotated approx. 90 degrees from its normal position. PPE-gamma-lactam crystals were subjected to 'pH-jumps' by placing the crystals in a buffer of increased pH prior to freezing for data collection. The results indicate that the conformation of the gamma-lactam-derived acyl-enzyme species in the PPE active site is dependent on pH, a result having implications for the analysis of other serine protease-inhibitor structures at non-catalytic pH values. The results help to define the stereoelectronic relationship between the ester of the acyl-enzyme complex, the side chain of His-57 and the incoming nucleophile during the reversible (de)acylation steps, implying it is closely analogous to the hydrolytic deacylation step during catalytic peptide hydrolysis.

SUBMITTER: Wright PA

PROVIDER: S-EPMC1221368 | biostudies-other | 2000 Oct

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

The specificity of purified porcine pancreatic elastase.

Project description:An electrophoretically homogeneous elastase preparation free from tryptic and chymotryptic activities was obtained by chromatography on DEAE-Sephadex and CM-cellulose. This preparation exhibits a narrower specificity towards peptide bonds than that observed by Naughton & Sanger (1961). With oxidized insulin B chain as substrate, the fastest breaks occur between alanine-14 and leucine-15 and between valine-18 and cysteic acid-19. The bond between glycine-23 and phenylalanine-24 is also efficiently hydrolysed. Other bonds hydrolysed are that between valine-12 and glutamic acid-13 and that between serine-9 and histidine-10. Oxidized insulin A chain is hydrolysed only at one of two points, between alanine-8 and serine-9 or between serine-12 and leucine-13, and the rate of hydrolysis is very low.

| S-EPMC1184789 | biostudies-other

Stabilization of porcine pancreatic elastase crystals by glutaraldehyde cross-linking.

Project description:Elastase is a serine protease from the chymotrypsin family of enzymes with the ability to degrade elastin, an important component of connective tissues. Excessive elastin proteolysis leads to a number of pathological diseases. Porcine pancreatic elastase (PPE) is often used for drug development as a model for human leukocyte elastase (HLE), with which it shares high sequence identity. Crystals of PPE were grown overnight using sodium sulfate and sodium acetate at acidic pH. Cross-linking the crystals with glutaraldehyde was needed to resist the soaking procedure with a diethyl N-(methyl)pyridinyl-substituted oxo-?-lactam inhibitor. Crystals of PPE bound to the inhibitor belonged to the orthorhombic space group P2?2?2?, with unit-cell parameters a = 51.0, b = 58.3, c = 74.9?Å, and diffracted to 1.8?Å resolution using an in-house X-ray source.

| S-EPMC4601602 | biostudies-literature

Evidence for the amino acid sequence of porcine pancreatic elastase.

Project description:The preparation and purification of tryptic peptides from aminoethylated Dip-elastase and [(14)C]carboxymethylated Dip-elastase, and of peptic peptides from native elastase is described. A summary of the results of chemical studies used to elucidate the amino acid sequence of these peptides is presented. Full details are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50016 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 1-20. These results, together with those from previously published papers, are used to establish the complete amino acid sequence of elastase, which is a single polypeptide chain of 240 residues, molecular weight 25900, containing four disulphide bridges.

| S-EPMC1177525 | biostudies-other

A titratable murine model of progressive emphysema using tracheal porcine pancreatic elastase.

Project description:Progressive emphysema often leads to end-stage lung disease. Most mouse models of emphysema are typically modest (i.e. cigarette smoke exposure), and changes over time are difficult to quantify. The tracheal porcine pancreatic elastase model (PPE) produces severe injury, but the literature is conflicted as to whether emphysema improves, is stable, or progresses over time. We hypothesized a threshold of injury below which repair would occur and above which emphysema would be stable or progress. We treated 8-week-old C57BL6 mixed sex mice with 0, 0.5, 2, or 4 activity units of PPE in 100 µL PBS and performed lung stereology at 21 and 84 days. There were no significant differences in weight gain or mouse health. Despite minimal emphysema at 21-days in the 0.5 units group (2.8 µm increased mean linear intercept, MLI), MLI increased by 4.6 µm between days 21 and 84 (p = 0.0007). In addition to larger MLI at 21 days in 2- and 4-unit groups, MLI increases from day 21 to 84 were 17.2 and 34 µm respectively (p = 0.002 and p = 0.0001). Total lung volume increased, and alveolar surface area decreased with time and injury severity. Contrary to our hypothesis, we found no evidence of alveolar repair over time. Airspace destruction was both progressive and accelerative. Future mechanistic studies in lung immunity, mechano-biology, senescence, and cell-specific changes may lead to novel therapies to slow or halt progressive emphysema in humans.

| S-EPMC10502133 | biostudies-literature

Transcriptomic profiling of murine aneurysm formation after porcine pancreatic elastase infusion

Project description:In the present work, we aimed to investigate the changes in total RNA expression after porcine pancreatic elastase (PPE) instillation in C57BL/6 mice.

2022-01-01 | GSE153097 | GEO

Structure of the complex of porcine pancreatic elastase with a trimacrocyclic peptide inhibitor FR901451.

Project description:Porcine pancreatic elastase (PPE) resembles the attractive drug target leukocyte elastase, which has the ability to degrade connective tissue in the body. The crystal structure of PPE complexed with a novel trimacrocyclic peptide inhibitor, FR901451, was solved at 1.9 A resolution. The inhibitor occupied the subsites S3 through S3' of PPE and induced conformational changes in the side chains of Arg64 and Arg226, which are located at the edges of the substrate-binding cleft. Structural comparison of five PPE-inhibitor complexes, including the FR901451 complex and non-ligated PPE, reveals that the residues forming the S2, S1, S1' and S2' subsites in the cleft are rigid, but the two arginine residues playing a part in the S3 and S3' subsites are flexible. Structural comparison of PPE with human leukocyte elastase (HLE) implies that the inhibitor binds to HLE in a similar manner to the FR901451-PPE complex. This structural insight may help in the design of potent elastase inhibitors.

| S-EPMC1978120 | biostudies-literature

Tris(hydroxymethyl)aminomethane induces conformational change and crystal-packing contraction of porcine pancreatic elastase.

Project description:Porcine pancreatic elastase (PPE) was crystallized under new sulfate-free conditions containing 0.3 M NaCl and 50 mM tris(hydroxymethyl)aminomethane-HCl at pH 7.0. The crystal structure determined at 1.5 angstroms resolution had a unique conformation in four regions which contained loop portions. A chloride ion was bound near the catalytic triad instead of the sulfate ion in PDB entry 1qnj, a typical PPE crystal structure. However, the chloride ion did not affect the configuration of the catalytic triad. A tris(hydroxymethyl)aminomethane (Tris) molecule was bound to the S4 and S5 subsites in place of the adjacent molecule in the 1qnj crystal and played a significant role in the structural change of the region. The distortion in this region may subsequently have induced conformational changes in the other three regions. The fact that Tris and these four regions make a diagonal line in the ac plane may have affected the crystal-packing contraction along the a and c axes in the crystal compared with the typical crystal.

| S-EPMC2242949 | biostudies-literature

The primary structure of porcine pancreatic elastase. The N-terminus and disulphide bridges.

Project description:1. The amino acid composition and N-terminal groups of purified elastase show that it is a single peptide chain of 234 residues. 2. The N-terminal sequence is Val-Val-Gly-Gly-Thr-Glu-. 3. The sequences around the four disulphide bridges were determined by using a ;diagonal' electrophoretic technique. 4. These four bridges are homologous with the four common to bovine trypsin and chymotrypsin. 5. Out of 83 residues of the elastase sequence so far determined, 43 are homologous with similar regions of trypsin and chymotrypsin. 6. The evolutionary ancestry of these enzymes is discussed.

| S-EPMC1270434 | biostudies-other

Lung Immune Cells in Wildtype and Cela1-/- Mice 21 Days After Tracheal Porcine Pancreatic Elastase

Project description:8-10 week old wildtype and Cela1-/- in C57BL6 background were treated with 2 units of tracheal porcine pancreatic elastase or PBS and on day 21 lungs were collected, flow sorted, and libraries created from lung cells of 3 mice per group using 10X Chromium controller and cellplex lipid hashing oligos.

2022-09-23 | E-MTAB-12097 | biostudies-arrayexpress

Crystallographic analyses of isoquinoline complexes reveal a new mode of metallo-β-lactamase inhibition.

Project description:Crystallographic analyses of the VIM-5 metallo-β-lactamase (MBL) with isoquinoline inhibitors reveal non zinc ion binding modes. Comparison with other MBL-inhibitor structures directed addition of a zinc-binding thiol enabling identification of potent B1 MBL inhibitors. The inhibitors potentiate meropenem activity against clinical isolates harboring MBLs.

| S-EPMC5516270 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data