scholarly journals Serpins in cartilage and osteoarthritis: what do we know?

2021 ◽  
Author(s):  
David J. Wilkinson
Keyword(s):  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Cartilage Destruction ◽  
Inhibition Mechanism ◽  
Serine Proteinases ◽  
Surface Receptors ◽  
Monogenic Disorders ◽  
Joint Disorder ◽  
Proteinase Inhibition ◽  
First Time

Serpins (serine proteinase inhibitors) are an ancient superfamily of structurally similar proteins, the majority of which use an elegant suicide inhibition mechanism to target serine proteinases. Despite likely evolving from a single common ancestor, the 36 human serpins have established roles regulating diverse biological processes, such as blood coagulation, embryonic development and extracellular matrix (ECM) turnover. Genetic mutations in serpin genes underpin a host of monogenic disorders — collectively termed the ‘serpinopathies’ — but serpin dysregulation has also been shown to drive pathological mechanisms in many common diseases. Osteoarthritis is a degenerative joint disorder, characterised by the progressive destruction of articular cartilage. This breakdown of the cartilage is driven by the metalloproteinases, and it has long been established that an imbalance of metalloproteinases to their inhibitors is of critical importance. More recently, a role for serine proteinases in cartilage destruction is emerging; including the activation of latent matrix metalloproteinases and cell-surface receptors, or direct proteolysis of the ECM. Serpins likely regulate these processes, as well as having roles beyond serine proteinase inhibition. Indeed, serpins are routinely observed to be highly modulated in osteoarthritic tissues and fluids by ‘omic analysis, but despite this, they are largely ignored. Confusing nomenclature and an underappreciation for the role of serine proteinases in osteoarthritis (OA) being the likely causes. In this narrative review, serpin structure, biochemistry and nomenclature are introduced, and for the first time, their putative importance in maintaining joint tissues — as well as their dysregulation in OA — are explored.

scholarly journals Proteinase inhibitors in rat serum. Purification and partial characterization of three functionally distinct trypsin inhibitors

1984 ◽  
Vol 218 (3) ◽  
pp. 953-959 ◽  
Author(s):  
L Kuehn ◽  
M Rutschmann ◽  
B Dahlmann ◽  
H Reinauer
Keyword(s):  
Proteinase Inhibitor ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
The Other ◽  
Serine Proteinases ◽  
Rat Serum ◽  
Apparent Homogeneity ◽  
Human Counterpart ◽  
Proteinase Inhibitor Ii

Three different serine proteinase inhibitors were isolated from rat serum and purified to apparent homogeneity. One of the inhibitors appears to be homologous to alpha 1-proteinase inhibitor isolated from man and other species, but the other two, designated rat proteinase inhibitor I and rat proteinase inhibitor II, seem to have no human counterpart. alpha 1-Proteinase inhibitor (Mr 55000) inhibits trypsin, chymotrypsin and elastase, the three serine proteinases tested. Rat proteinase inhibitor I (Mr 66000) is active towards trypsin and chymotrypsin, but is inactive towards elastase. Rat proteinase inhibitor II (Mr 65000) is an effective inhibitor of trypsin only. Their contributions to the trypsin-inhibitory capacity of rat serum are about 68, 14 and 18% for alpha 1-proteinase inhibitor, rat proteinase inhibitor I and rat proteinase inhibitor II respectively.

Functional proteomics of kallikrein-related peptidases in ovarian cancer ascites fluid

2010 ◽  
Vol 391 (4) ◽  
Author(s):  
Katerina Oikonomopoulou ◽  
Ihor Batruch ◽  
Chris R. Smith ◽  
Antoninus Soosaipillai ◽  
Eleftherios P. Diamandis ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Cancer Cell Line ◽  
Malignant Ascites ◽  
Ascites Fluid ◽  
Clinical Samples ◽  
Serine Proteinases ◽  
Α2 Macroglobulin

Abstract Kallikrein-related peptidases (KLKs) are secreted serine proteinases with trypsin or chymotrypsin-like activity. Several family members, such as KLKs 6 and 10, are potential ovarian cancer biomarkers. Recently, using a newly developed assay for active KLK6, we found that only a very small proportion of immunoreactive KLK6 in tumor-derived clinical samples (malignant ascites fluid), in cerebrospinal fluid, and in cancer cell line supernatants is enzymatically active. We therefore hypothesized that a proportion of other immunoreactive KLKs in such samples could be present, but might be partly complexed to endogenous serine proteinase inhibitors. Using a combination of immunological isolation of the enzymes, activity-based probe analysis and proteomics, we identified active KLK10 in ovarian cancer ascites and we provide preliminary data that the activity of other KLKs present in these samples can be decreased by known proteinase inhibitors (e.g., α2-macroglobulin, α1-antitrypsin). Our data suggest that the enzymatic activity of ovarian cancer-released KLKs that are detected by regular immunoassays is low in vivo and very likely regulated by proteinase inhibitors.

Novel roles of protease inhibitors in infection and inflammation

2002 ◽  
Vol 30 (2) ◽  
pp. 116-120 ◽  
Author(s):  
P. S. Hiemstra
Keyword(s):  
Extracellular Matrix ◽  
Protease Inhibitors ◽  
Neutrophil Elastase ◽  
Proteinase Inhibitor ◽  
Tissue Repair ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Serine Proteinases ◽  
Matrix Synthesis ◽  
Infection And Inflammation

The local balance between proteinase inhibitors and proteinases determines local proteolytic activity. Various studies have demonstrated the importance of serine proteinase inhibitors in regulating the activity of serine proteinases that are released by leucocytes during inflammation. Recently it has been shown that these inhibitors may also display functions that are distinct from those associated with the inhibition of leucocyte-derived proteinases. In this review the results of selected studies focusing on three inhibitors of neutrophil elastase, i.e. α1-proteinase inhibitor, secretory leucocyte proteinase inhibitor and elafin, are presented, with the aim of illustrating their possible involvement in the regulation of inflammation, host defence against infection, tissue repair and extracellular matrix synthesis.

scholarly journals Inactivation of papain by antithrombin due to autolytic digestion: a model of serpin inactivation of cysteine proteinases

1998 ◽  
Vol 335 (3) ◽  
pp. 701-709 ◽  
Author(s):  
Ingemar BJÖRK ◽  
Kerstin NORDLING ◽  
Elke RAUB-SEGALL ◽  
Ulf HELLMAN ◽  
Steven T. OLSON
Keyword(s):  
Cysteine Proteinase ◽  
Cathepsin L ◽  
Serine Proteinase ◽  
Peptide Bond ◽  
Enzyme Inactivation ◽  
Serine Proteinases ◽  
Cysteine Proteinases ◽  
Sds Page ◽  
Reaction Proceeds ◽  
Proteinase Inhibition

Cross-class inhibition of cysteine proteinases by serpins differs from serpin inhibition of serine proteinases primarily in that no stable serpin–cysteine proteinase complex can be demonstrated. This difference in reaction mechanism was elucidated by studies of the inactivation of the cysteine proteinases, papain and cathepsin L, by the serpin antithrombin. The two proteinases were inactivated with second-order rate constants of (1.6±0.1)×103 and (8.6±0.4)×102 M-1·s-1 respectively. An antithrombin to papain inactivation stoichiometry of ∼ 3 indicated extensive cleavage of the inhibitor concurrent with enzyme inactivation, a behaviour verified by SDS/PAGE. N-terminal sequence analyses showed cleavage predominantly at the P2–P1 bond, but also at the P2´–P3´ bond of antithrombin. The papain band in SDS/PAGE progressively disappeared on reaction of the enzyme with increasing amounts of antithrombin, but no band representing a stable antithrombin–papain complex appeared. SDS/PAGE with 125I-labelled papain showed that the disappearance of papain was caused by cleavage of the enzyme into small fragments. These results suggest a mechanism in which papain attacks a peptide bond in the reactive-bond loop of antithrombin adjacent to that involved in serine proteinase inhibition. The reaction proceeds, similarly to that between serpins and serine proteinases, to form an inactive acyl-intermediate complex, although with the substrate pathway dominating in the papain reaction. In this complex, papain is highly susceptible to proteolysis and is degraded by still active papain, which greatly decreases the lifetime of the complex and results in liberation of fragmented, inactive enzyme. This model may have relevance also for the inactivation of physiologically or pathologically important cysteine proteinases by serpins.

A Novel Serpin Expressed by Blood-Borne Microfilariae of the Parasitic Nematode Brugia malayi Inhibits Human Neutrophil Serine Proteinases

Blood ◽  
1999 ◽  
Vol 94 (4) ◽  
pp. 1418-1428 ◽  
Author(s):  
Xingxing Zang ◽  
Maria Yazdanbakhsh ◽  
Haobo Jiang ◽  
Michael R. Kanost ◽  
Rick M. Maizels
Keyword(s):  
Human Neutrophil ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Brugia Malayi ◽  
Cathepsin G ◽  
Cdna Libraries ◽  
Human Neutrophil Elastase ◽  
Serine Proteinases ◽  
Serpin Gene ◽  
Wide Range

Abstract Serine proteinase inhibitors (serpins) play a vital regulatory role in a wide range of biological processes, and serpins from viruses have been implicated in pathogen evasion of the host defence system. For the first time, we report a functional serpin gene from nematodes that may function in this manner. This gene, named Bm-spn-2, has been isolated from the filarial nematode Brugia malayi, a causative agent of human lymphatic filariasis. Polymerase chain reaction (PCR) and Western blot experiments indicate that Bm-spn-2 is expressed only by microfilariae (Mf), which are the long-lived blood-dwelling larval stage. A survey of the greater than 14,000 expressed sequence tags (ESTs) from B malayi deposited in dbEST shows that greater than 2% of the ESTs sequenced from Mf cDNA libraries correspond to Bm-spn-2. Despite its abundance in the microfilarial stage, Bm-spn-2 has not been found in any other point in the life cycle. The predicted protein encoded byBm-spn-2 contains 428 amino acids with a putative signal peptide. Antibodies to recombinant Bm-SPN-2 protein react specifically with a 47.5-kD native protein in Mf extract. Bm-SPN-2 is one of the largest of the 93 known serpins, due to a 22 amino acid carboxy-terminal extension, and contains the conserved serpin signature sequence. Outside these regions, levels of homology are low, and only a distant relationship can been seen to a Caenorhabditis elegansserpin. The Bm-spn-2 gene contains 6 introns, 2 of which appear to be shared by both nematode species. The B malayi introns have an extended and conserved 3′ splice site and are relatively large compared with C elegans. A panel of mammalian serine proteinases were screened and Bm-SPN-2 protein was found to specifically inhibit enzymatic activity of human neutrophil cathepsin G and human neutrophil elastase, but not a range of other serine proteinases. It is possible that Bm-SPN-2 could function as a stage-specific serpin in the blood environment of the microfilarial parasite in protection from human immunity and thus may be a good candidate for protective vaccine.

A Novel Serpin Expressed by Blood-Borne Microfilariae of the Parasitic Nematode Brugia malayi Inhibits Human Neutrophil Serine Proteinases

Blood ◽  
1999 ◽  
Vol 94 (4) ◽  
pp. 1418-1428 ◽  
Author(s):  
Xingxing Zang ◽  
Maria Yazdanbakhsh ◽  
Haobo Jiang ◽  
Michael R. Kanost ◽  
Rick M. Maizels
Keyword(s):  
Human Neutrophil ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Brugia Malayi ◽  
Cathepsin G ◽  
Cdna Libraries ◽  
Human Neutrophil Elastase ◽  
Serine Proteinases ◽  
Serpin Gene ◽  
Wide Range

Serine proteinase inhibitors (serpins) play a vital regulatory role in a wide range of biological processes, and serpins from viruses have been implicated in pathogen evasion of the host defence system. For the first time, we report a functional serpin gene from nematodes that may function in this manner. This gene, named Bm-spn-2, has been isolated from the filarial nematode Brugia malayi, a causative agent of human lymphatic filariasis. Polymerase chain reaction (PCR) and Western blot experiments indicate that Bm-spn-2 is expressed only by microfilariae (Mf), which are the long-lived blood-dwelling larval stage. A survey of the greater than 14,000 expressed sequence tags (ESTs) from B malayi deposited in dbEST shows that greater than 2% of the ESTs sequenced from Mf cDNA libraries correspond to Bm-spn-2. Despite its abundance in the microfilarial stage, Bm-spn-2 has not been found in any other point in the life cycle. The predicted protein encoded byBm-spn-2 contains 428 amino acids with a putative signal peptide. Antibodies to recombinant Bm-SPN-2 protein react specifically with a 47.5-kD native protein in Mf extract. Bm-SPN-2 is one of the largest of the 93 known serpins, due to a 22 amino acid carboxy-terminal extension, and contains the conserved serpin signature sequence. Outside these regions, levels of homology are low, and only a distant relationship can been seen to a Caenorhabditis elegansserpin. The Bm-spn-2 gene contains 6 introns, 2 of which appear to be shared by both nematode species. The B malayi introns have an extended and conserved 3′ splice site and are relatively large compared with C elegans. A panel of mammalian serine proteinases were screened and Bm-SPN-2 protein was found to specifically inhibit enzymatic activity of human neutrophil cathepsin G and human neutrophil elastase, but not a range of other serine proteinases. It is possible that Bm-SPN-2 could function as a stage-specific serpin in the blood environment of the microfilarial parasite in protection from human immunity and thus may be a good candidate for protective vaccine.

13C- and 1H-NMR studies of oxyanion and tetrahedral intermediate stabilization by the serine proteinases: optimizing inhibitor warhead specificity and potency by studying the inhibition of the serine proteinases by peptide-derived chloromethane and glyoxal inhibitors

2007 ◽  
Vol 35 (3) ◽  
pp. 566-570 ◽  
Author(s):  
J.P.G. Malthouse
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Serine Proteinases ◽  
Nmr Studies ◽  
Oxyanion Hole ◽  
Optimal Position ◽  
Reversible Inhibitors ◽  
Tetrahedral Intermediate

Catalysis by the serine proteinases proceeds via a tetrahedral intermediate whose oxyanion is stabilized by hydrogen-bonding in the oxyanion hole. There have been extensive 13C-NMR studies of oxyanion and tetrahedral intermediate stabilization in trypsin, subtilisin and chymotrypsin using substrate-derived chloromethane inhibitors. One of the limitations of these inhibitors is that they irreversibly alkylate the active-site histidine residue which results in the oxyanion not being in the optimal position in the oxyanion hole. Substrate-derived glyoxal inhibitors are reversible inhibitors which, if they form tetrahedral adducts in the same way as substrates form tetrahedral intermediates, will overcome this limitation. Therefore we have synthesized 13C-enriched substrate-derived glyoxal inhibitors which have allowed us to use 13C-NMR and 1H-NMR to determine how they interact with proteinases. It is hoped that these studies will help in the design of specific and highly potent warheads for serine proteinase inhibitors.

Development of In Situ Zymography to Localize Active Matrix Metalloproteinase-7 (Matrilysin-1)

2005 ◽  
Vol 53 (10) ◽  
pp. 1227-1234 ◽  
Author(s):  
Ryoichi Nemori ◽  
Masayoshi Yamamoto ◽  
Fumio Kataoka ◽  
Gakuji Hashimoto ◽  
Hiroshi Arakatsu ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Carcinoma Cell ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Serine Proteinases ◽  
Active Matrix ◽  
Tissue Sections ◽  
Matrix Metalloproteinase 7 ◽  
In Situ Zymography

Matrix metalloproteinase-7 (MMP-7) is upregulated during carcinogenesis and its expression correlates with metastasis of human endometrial and gastrointestinal carcinomas. In the present study, we have developed a new method to localize the activity of MMP-7 within tissues. Polyethylene terephthalate films were uniformly coated with crosslinked carboxymethylated transferrin (CCm-Tf) as a substrate and incubated with frozen tissue sections mounted on the films. CCm-Tf on the films was degraded selectively by MMP-7, but showed little or no susceptibility to MMP-1, -2, -3, -9, or -13; MT1-MMP; MT3-MMP; or ADAMTS4. Although some serine proteinases such as elastase also digested CCm-Tf, CCm-Tf films impregnated with serine proteinase inhibitors prevented the digestion. When frozen sections of human endometrial carcinoma and lung carcinoma tissues were incubated on CCm-Tf films or those treated with proteinase inhibitors, the activity was detected in the carcinoma cell nests, where MMP-7 was immunolocalized. The present in situ zymography using CCm-Tf may be a useful method to analyze the functions of MMP-7 in pathophysiological conditions.

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