The Secreted Aminopeptidase of (PaAP).

is an opportunistic pathogen that causes severe infections in compromised hosts. infections are difficult to treat because of the inherent ability of the bacteria to develop antibiotic resistance, secrete a variety of virulence factors, and form biofilms. The secreted aminopeptidase (PaAP) is an emerging virulence factor, key in providing essential low molecular weight nutrients and a cardinal modulator of biofilm development.

Extracellular proteolytic activation of Pseudomonas aeruginosa aminopeptidase (PaAP) and insight into the role of its non-catalytic N-terminal domain.

Pseudomonas aeruginosa secretes several endopeptidases, including elastase, alkaline proteinase (Apr), a lysine-specific endopeptidase (LysC), and an aminopeptidase (PaAP), all of which are important virulence factors. Activation of the endopeptidases requires removal of an inhibitory N-terminal propeptide. Activation of pro-PaAP, in contrast, requires C-terminal processing.

Analysis of Procollagen C-Proteinase Enhancer-1/Glycosaminoglycan Binding Sites and of the Potential Role of Calcium Ions in the Interaction.

In this study, we characterize the interactions between the extracellular matrix protein, procollagen C-proteinase enhancer-1 (PCPE-1), and glycosaminoglycans (GAGs), which are linear anionic periodic polysaccharides. We applied molecular modeling approaches to build a structural model of full-length PCPE-1, which is not experimentally available, to predict GAG binding poses for various GAG lengths, types and sulfation patterns, and to determine the effect of calcium ions on the binding. The computational data are analyzed and discussed in the context of the experimental results previously obtained using surface plasmon resonance binding assays.

Ascorbic Acid Promotes Procollagen C-Proteinase Enhancer 1 Expression, Secretion, and Cell Membrane Localization.

Removal of the C-propeptide from fibrillar procollagens is essential for collagen fibril assembly. The reaction is catalyzed by bone morphogenetic protein-1/tolloid-like proteinases and is accelerated by procollagen C-proteinase enhancer 1 (PCPE-1), an extracellular matrix glycoprotein that binds to the procollagen C-propeptide and its expression overlaps that of collagen. Ascorbic acid (Asc) is vital for collagen hydroxylation, folding, and secretion.

COL1A1 C-propeptide mutations cause ER mislocalization of procollagen and impair C-terminal procollagen processing.

Mutations in the type I procollagen C-propeptide occur in ~6.5% of Osteogenesis Imperfecta (OI) patients. They are of special interest because this region of procollagen is involved in α chain selection and folding, but is processed prior to fibril assembly and is absent in mature collagen fibrils in tissue.

Procollagen C-Proteinase Enhancer 1 (PCPE-1) in Liver Fibrosis.

Fibrosis is characterized by excessive deposition of collagen and additional extracellular matrix (ECM) components in response to chronic injuries. Liver fibrosis often results from chronic hepatitis C virus infection and alcohol abuse that can deteriorate to cirrhosis and liver failure. Current noninvasive diagnostic methods of liver fibrosis are limited in their ability to detect and differentiate between early and intermediate stages of fibrosis.

Data comparing the plasma levels of procollagen C-proteinase enhancer 1 (PCPE-1) in healthy individuals and liver fibrosis patients.

This article provides a protocol for determination of human procollagen C-proteinase enhancer 1 (PCPE-1) concentrations by ELISA. The inter-assay and intra-assay coefficients of variability are given and so are the average plasma concentrations of PCPE-1 in healthy (control) individuals and liver fibrosis patients.

Data comparing the kinetics of procollagen type I processing by bone morphogenetic protein 1 (BMP-1) with and without procollagen C-proteinase enhancer 1 (PCPE-1).

This article provides kinetic constants for C-terminal processing of procollagen type I by bone morphogenetic protein 1 (BMP-1; the major procollagen C-proteinase), a reaction stimulated by the connective tissue glycoprotein procollagen C-proteinase enhancer 1 (PCPE-1). Reported are , , and / (catalytic coefficient) values for BMP-1 alone, BMP-1 with intact PCPE-1, BMP-1 with the CUB (Complement C1r/C1s, Uegf, BMP-1) domains fragment of PCPE-1 as well as its NTR (netrin-like) domain.

Anti-fibrotic characteristics of Vγ9+ γδ T cells in systemic sclerosis.

Objectives: γδ T cells of the Vγ9Vδ2 subtype secrete anti-fibrotic cytokines upon isopentenyl pyrophosphate (IPP) stimulation. In this study, we sought to compare IPP and Zoledronate, an up-regulator of IPP, effects on proliferation and cytokine secretion of Vγ9+ T cells from systemic sclerosis (SSc) patients and healthy controls (HCs). We also examined the effect of IPP-triggered peripheral blood mononuclear cells (PBMC) on fibroblast procolla- gen secretion.

Correction: Procollagen C-Proteinase Enhancer 1 (PCPE-1) as a Plasma Marker of Muscle and Liver Fibrosis in Mice.

[This corrects the article DOI: 10.1371/journal.pone.

Procollagen C-Proteinase Enhancer 1 (PCPE-1) as a Plasma Marker of Muscle and Liver Fibrosis in Mice.

Current non-invasive diagnostic methods of fibrosis are limited in their ability to identify early and intermediate stages of fibrosis and assess the efficacy of therapy. New biomarkers of fibrosis are therefore constantly sought for, leading us to evaluate procollagen C-proteinase enhancer 1 (PCPE-1), a fibrosis-related extracellular matrix glycoprotein, as a plasma marker of fibrosis. A sandwich ELISA that permitted accurate measurements of PCPE-1 concentrations in mouse plasma was established.

The NTR domain of procollagen C-proteinase enhancer-1 (PCPE-1) mediates PCPE-1 binding to syndecans-1, -2 and -4 as well as fibronectin.

Procollagen C-proteinase enhancer 1 (PCPE-1) is an extracellular matrix glycoprotein that can stimulate procollagen processing by procollagen C-proteinases (PCPs) such as bone morphogenetic protein-1 (BMP-1). PCPE-1 consists of two CUB domains that bind to the procollagen C-propeptide and are responsible for enhancing activity and a netrin-like (NTR) domain that binds to BMP-1 as well as heparin and heparan sulfate. The NTR domain also mediates binding of PCPE-1 to cells, an interaction inhibited by heparin, thus suggesting involvement of cell membrane heparan-sulfate proteoglycans (HSPGs).

Elastinolytic and proteolytic enzymes.

Pseudomonas aeruginosa secretes into its environment at least seven extracellular proteases: pseudolysin (LasB protease; elastase), aeruginolysin (alkaline proteinase), staphylolysin (staphylolytic endopeptidase; LasA protease), lysyl endopeptidase (protease IV; PrpL), PASP (P. aeruginosa small protease), LepA (Large ExoProtease A), and an aminopeptidase. Their action on host proteins, both individually and synergistically, plays important roles in pathogenesis of P.

Extended interaction network of procollagen C-proteinase enhancer-1 in the extracellular matrix.

PCPE-1 (procollagen C-proteinase enhancer-1) is an extracellular matrix glycoprotein that can stimulate procollagen processing by procollagen C-proteinases such as BMP-1 (bone morphogenetic protein 1). PCPE-1 interacts with several proteins in addition to procollagens and BMP-1, suggesting that it could be involved in biological processes other than collagen maturation. We thus searched for additional partners of PCPE-1 in the extracellular matrix, which could provide new insights into its biological roles.

Staphylolysin is an effective therapeutic agent for Staphylococcus aureus experimental keratitis.

Background: Therapy of S. aureus keratitis is increasingly challenging due to emerging resistant strains. Staphylolysin (LasA protease) is a staphylolytic endopeptidase secreted by Pseudomonas aeruginosa.

Quantification of human serum procollagen C-proteinase enhancer (hsPCPE) glycopattern.

Background: Procollagen C-proteinase enhancer 1 (PCPE1), a glycoprotein secreted from differentiating osteoblast, enhances the rate-limiting step of collagen type I fibrillar formation. It is expressed and secreted by cells that produce collagen type I and has the potential to be a marker for bone pathologies.

Methods: We developed an assay to quantify PCPE glycopattern based on isoelectric focusing (IEF) and detection with a bio-imaging camera (coefficient of variation within and between assays, 15% and 20%, respectively).

COL1 C-propeptide cleavage site mutations cause high bone mass osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is most often caused by mutations in the type I procollagen genes (COL1A1/COL1A2). We identified two children with substitutions in the type I procollagen C-propeptide cleavage site, which disrupt a unique processing step in collagen maturation and define a novel phenotype within OI. The patients have mild OI caused by mutations in COL1A1 (Patient 1: p.

Identification of binding partners interacting with the α1-N-propeptide of type V collagen.

The predominant form of type V collagen is the [α1(V)]₂α2(V) heterotrimer. Mutations in COL5A1 or COL5A2, encoding respectively the α1(V)- and α2(V)-collagen chain, cause classic EDS (Ehlers-Danlos syndrome), a heritable connective tissue disorder, characterized by fragile hyperextensible skin and joint hypermobility. Approximately half of the classic EDS cases remain unexplained.

Binding of procollagen C-proteinase enhancer-1 (PCPE-1) to heparin/heparan sulfate: properties and role in PCPE-1 interaction with cells.

Procollagen C-proteinase enhancer-1 (PCPE-1) is an extracellular matrix (ECM) glycoprotein that can stimulate procollagen processing by procollagen C-proteinases (PCPs) such as bone morphogenetic protein-1 (BMP-1). The PCPs can process additional extracellular protein precursors and play fundamental roles in developmental processes and assembly of the ECM. The stimulatory activity of PCPE-1 is restricted to the processing of fibrillar procollagens, suggesting PCPE-1 is a specific regulator of collagen deposition.

The collagen V homotrimer [alpha1(V)](3) production is unexpectedly favored over the heterotrimer [alpha1(V)](2)alpha2(V) in recombinant expression systems.

Collagen V, a fibrillar collagen with important functions in tissues, assembles into distinct chain associations. The most abundant and ubiquitous molecular form is the heterotrimer [alpha1(V)](2)alpha2(V). In the attempt to produce high levels of recombinant collagen V heterotrimer for biomedical device uses, and to identify key factors that drive heterotrimeric chain association, several cell expression systems (yeast, insect, and mammalian cells) have been assayed by cotransfecting the human proalpha1(V) and proalpha2(V) chain cDNAs.

Functional study of elafin cleaved by Pseudomonas aeruginosa metalloproteinases.

Elafin is a 6-kDa innate immune protein present at several epithelial surfaces including the pulmonary epithelium. It is a canonical protease inhibitor of two neutrophil serine proteases [neutrophil elastase (NE) and proteinase 3] with the capacity to covalently bind extracellular matrix proteins by transglutamination. In addition to these properties, elafin also possesses antimicrobial and immunomodulatory activities.

Role of the netrin-like domain of procollagen C-proteinase enhancer-1 in the control of metalloproteinase activity.

The netrin-like (NTR) domain is a feature of several extracellular proteins, most notably the N-terminal domain of tissue inhibitors of metalloproteinases (TIMPs), where it functions as a strong inhibitor of matrix metalloproteinases and some other members of the metzincin superfamily. The presence of a C-terminal NTR domain in procollagen C-proteinase enhancers (PCPEs), proteins that stimulate the activity of astacin-like tolloid proteinases, raises the possibility that this might also have inhibitory activity. Here we show that both long and short forms of the PCPE-1 NTR domain, the latter beginning at the N-terminal cysteine known to be critical for TIMP activity, show no inhibition, at micromolar concentrations, of several members of the metzincin superfamily, including matrix metalloproteinase-2, bone morphogenetic protein-1 (a tolloid proteinase), and different ADAMTS (a disintegrin and a metalloproteinase with thrombospondin motifs) proteinases from the adamalysin family.

Evaluation of Pseudomonas aeruginosa staphylolysin (LasA protease) in the treatment of methicillin-resistant Staphylococcus aureus endophthalmitis in a rat model.

Background: Therapy of S. aureus ocular infections is increasingly challenging due to emerging resistant strains. Staphylolysin (also called LasA protease) is a staphylolytic endopeptidase secreted by Pseudomonas aeruginosa.

Identification of critical residues in the propeptide of LasA protease of Pseudomonas aeruginosa involved in the formation of a stable mature protease.

LasA protease is a 20-kDa elastolytic and staphylolytic enzyme secreted by Pseudomonas aeruginosa. LasA is synthesized as a preproenzyme that undergoes proteolysis to remove a 22-kDa amino-terminal propeptide. Like the propeptides of other bacterial proteases, the LasA propeptide may act as an intramolecular chaperone that correctly folds the mature domain into an active protease.

Expression of procollagen C-proteinase enhancer-1 in the remodeling rat heart is stimulated by aldosterone.

Excessive collagen deposition is a common complication of myocardial infarction that causes progressive heart disease. Several pro-fibrotic cytokines and hormones, including aldosterone, control this process. Procollagen processing by procollagen C-proteinase(s) is critical for collagen deposition and is potentiated by procollagen C-proteinase enhancer proteins (PCPEs).