Binding of the Cysteine Proteinases Papain and Cathepsin B-like to Coated Laminin: Use of Synthetic Peptides from Laminin and from the Laminin Binding Region of the β1Integrin Subunit to Characterize the Binding Site

1998 ◽  
Vol 358 (2) ◽  
pp. 283-290 ◽  
Author(s):  
Véronique Dalet-Fumeron ◽  
Laziz Boudjennah ◽  
Maurice Pagano
Keyword(s):  
Binding Site ◽  
Cathepsin B ◽  
Synthetic Peptides ◽  
Cysteine Proteinases ◽  
Binding Region ◽  
Laminin Binding

Localization of a Vitronectin Binding Region of Plasminogen Activator Inhibitor-1

1995 ◽  
Vol 73 (05) ◽  
pp. 829-834 ◽  
Author(s):  
Jaya Padmanabhan ◽  
David C Sane
Keyword(s):  
Binding Site ◽  
Plasminogen Activator ◽  
Inhibitory Activity ◽  
Plasminogen Activator Inhibitor ◽  
Structural Homology ◽  
Binding Region ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

SummaryThe PAI-1 binding site for VN was studied using two independent methods. PAI-1 was cleaved by Staph V8 protease, producing 8 fragments, only 2 of which bound to [125I]-VN. These fragments were predicted to overlap between residues 91-130. Since PAI-2 has structural homology to PAI-1, but does not bind to vitronectin, chimeras of PAI-1 and PAI-2 were constructed. Four chimeras, containing PAI-1 residues 1-70,1-105,1-114, and 1-167 were constructed and expressed in vitro. PAI-1, PAI-2, and all of the chimeras retained inhibitory activity for t-PA, but only the chimera containing PAI-1 residues 1-167 formed a complex with VN. Together, these results predict that the VN binding site of PAI-1 is between residues 115-130.

scholarly journals The Structure of the Cysteine-Rich Domain of Plasmodium falciparum P113 Identifies the Location of the RH5 Binding Site

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Ivan Campeotto ◽  
Francis Galaway ◽  
Shahid Mehmood ◽  
Lea K. Barfod ◽  
Doris Quinkert ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Binding Site ◽  
Structural Information ◽  
Blood Stage ◽  
Site Directed Mutagenesis ◽  
Effective Vaccine ◽  
Binding Region ◽  
Fab Fragment ◽  
Content Type ◽  
Blood Stage Malaria

ABSTRACT Plasmodium falciparum RH5 is a secreted parasite ligand that is essential for erythrocyte invasion through direct interaction with the host erythrocyte receptor basigin. RH5 forms a tripartite complex with two other secreted parasite proteins, CyRPA and RIPR, and is tethered to the surface of the parasite through membrane-anchored P113. Antibodies against RH5, CyRPA, and RIPR can inhibit parasite invasion, suggesting that vaccines containing these three components have the potential to prevent blood-stage malaria. To further explore the role of the P113-RH5 interaction, we selected monoclonal antibodies against P113 that were either inhibitory or noninhibitory for RH5 binding. Using a Fab fragment as a crystallization chaperone, we determined the crystal structure of the RH5 binding region of P113 and showed that it is composed of two domains with structural similarities to rhamnose-binding lectins. We identified the RH5 binding site on P113 by using a combination of hydrogen-deuterium exchange mass spectrometry and site-directed mutagenesis. We found that a monoclonal antibody to P113 that bound to this interface and inhibited the RH5-P113 interaction did not inhibit parasite blood-stage growth. These findings provide further structural information on the protein interactions of RH5 and will be helpful in guiding the development of blood-stage malaria vaccines that target RH5. IMPORTANCE Malaria is a deadly infectious disease primarily caused by the parasite Plasmodium falciparum. It remains a major global health problem, and there is no highly effective vaccine. A parasite protein called RH5 is centrally involved in the invasion of host red blood cells, making it—and the other parasite proteins it interacts with—promising vaccine targets. We recently identified a protein called P113 that binds RH5, suggesting that it anchors RH5 to the parasite surface. In this paper, we use structural biology to locate and characterize the RH5 binding region on P113. These findings will be important to guide the development of new antimalarial vaccines to ultimately prevent this disease, which affects some of the poorest people on the planet.

scholarly journals A discontinuous factor H binding site in the third component of complement as delineated by synthetic peptides.

1988 ◽  
Vol 263 (24) ◽  
pp. 12147-12150 ◽  
Author(s):  
J D Lambris ◽  
D Avila ◽  
J D Becherer ◽  
H J Müller-Eberhard
Keyword(s):  
Binding Site ◽  
Synthetic Peptides ◽  
Factor H ◽  
The Third ◽  
Third Component Of Complement

scholarly journals Inhibition of cysteine proteinases and dipeptidyl peptidase I by egg-white cystatin

1984 ◽  
Vol 223 (1) ◽  
pp. 245-253 ◽  
Author(s):  
M J H Nicklin ◽  
A J Barrett
Keyword(s):  
Cathepsin B ◽  
Bond Cleavage ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dipeptidyl Peptidase ◽  
Egg White ◽  
Reversible Inhibitor ◽  
Cysteine Proteinases ◽  
Peptide Bond Cleavage ◽  
Specific Oxidation

The interactions between egg-white cystatin and the cysteine proteinases papain, human cathepsin B and bovine dipeptidyl peptidase I were studied. Cystatin was shown to be a competitive reversible inhibitor of cathepsin B (Ki 1.7 nM, k-1 about 2.3×10(-3) s-1). The inhibition of dipeptidyl peptidase I was shown to be reversible (Ki(app.) 0.22 nM, k-1 about 2.2×10(-3) s-1). Cystatin bound papain too tightly for Ki to be determined, but an upper limit of 5 pM was estimated. The association was a second-order process, with k+1 1.0×10(7) M-1×s-1. Papain was shown to form equimolar complexes with cystatin. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of complexes formed between papain or cathepsin B and an excess of cystatin showed no peptide bond cleavage after incubation for 72 h. The reaction of the active-site thiol group of papain with 5,5′-dithiobis-(2-nitrobenzoic acid) at pH 8 and 2,2′-dithiobispyridine at pH 4 was blocked by complex-formation. Dipeptidyl peptidase I and papain were found to compete for binding to cystatin, contrary to a previous report. The two major isoelectric forms of cystatin were found to have similar specific inhibitory activities for papain, and similar affinities for papain, cathepsin B and dipeptidyl peptidase I. This, together with specific oxidation of the N-terminal serine residue with periodate, showed the N-terminal amino group of cystatin 1 to be unimportant for inhibition. General citraconylation of amino groups resulted in a large decrease in the affinity of cystatin for dipeptidyl peptidase I. It is concluded that the interaction of cystatin with cysteine proteinases has many characteristics similar to those of an inhibitor such as aprotinin with serine proteinases.

Immunogenicity of synthetic peptides from the Sm31 antigen (cathepsin B) of the Schistosoma mansoni adult worms

2001 ◽  
Vol 23 (11) ◽  
pp. 567-573 ◽  
Author(s):  
Oscar Noya ◽  
Belkisyolé Alarcón De Noya ◽  
Diana E. Ballen ◽  
Henry Bermúdez ◽  
Daniel Bout ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Cathepsin B ◽  
Synthetic Peptides

The cysteine proteinases of Schistosoma mansoni cercariae

Parasitology ◽  
1997 ◽  
Vol 114 (2) ◽  
pp. 105-112 ◽  
Author(s):  
J. P. DALTON ◽  
K. A. CLOUGH ◽  
M. K. JONES ◽  
P. J. BRINDLEY
Keyword(s):  
Schistosoma Mansoni ◽  
Cathepsin B ◽  
Cathepsin L ◽  
Serine Proteinase ◽  
Skin Penetration ◽  
Scanning Electron Micrographs ◽  
Cysteine Proteinases ◽  
Similar Function ◽  
Substrate Preferences ◽  
Serine Proteinase Activity

Based on substrate preferences, cercariae of Schistosoma mansoni were seen to express both cathepsin L and cathepsin B cysteine proteinases, although the former activity was many -fold greater. Two cathepsin L activities identified in cercarial extracts by zymography co-migrated with activities in extracts of 3 h and 24 h schisotosomula and in extracts of adult worms. Since these enzymes have been implicated in haemoglob in digestion by adult worms, they may perform a similar function in schistosomula. Immunolocalization using scanning electron micrographs showed that cathepsin L and cathepsin B proteinases were present in the cercarial post-acetabular glands. In addition, cercarial serine proteinase activities considered to facilitate skin penetration efficiently cleaved the substrates Z-Gly-Pro-Arg-NHMec and Z-Gly-Pro-Lys-NHMec. Cercariae release most of this serine proteinase activity when induced to secrete the contents of their acetabular glands. In contrast, newly transformed 3 h and 24 h schistosomula did not express this activity.

scholarly journals The short-neurotoxin-binding regions on the α-chain of human and Torpedo californica acetylcholine receptors

1991 ◽  
Vol 274 (3) ◽  
pp. 849-854 ◽  
Author(s):  
K H Ruan ◽  
B G Stiles ◽  
M Z Atassi
Keyword(s):  
Binding Site ◽  
Acetylcholine Receptors ◽  
Binding Activity ◽  
Lower Activity ◽  
Binding Region ◽  
Torpedo Californica ◽  
Binding Regions ◽  
Alpha Bungarotoxin ◽  
Erabutoxin B ◽  
Low Activity

The continuous regions for short-neurotoxin binding on the alpha-chains of Torpedo californica (electric ray) and human acetylcholine receptors (AChR) were localized by reaction of 125I-labelled cobrotoxin (Cot) and erabutoxin b (Eb) with synthetic overlapping peptides spanning the entire extracellular part of the respective alpha-chains. On Torpedo AChR, five Cot-binding regions were found to reside within peptides alpha 1-16, alpha 23-38/alpha 34-49 overlap, alpha 100-115, alpha 122-138 and alpha 194-210. The Eb-binding regions were localized within peptides alpha 23-38/alpha 34-49/alpha 45-60 overlap, alpha 100-115 and alpha 122-138. The main binding activity for both toxins resided within region alpha 122-138. In previous studies we had shown that the binding of long alpha-neurotoxins [alpha-bungarotoxin (Bgt) and cobratoxin (Cbt)] involved the same regions on Torpedo AChR as well as an additional region within residues alpha 182-198. Thus region alpha 182-198, which is the strongest binding region for long neurotoxins on Torpedo AChR, was not a binding region for short neurotoxins. On human AChR, peptide alpha 122-138 possessed the highest activity with both toxins, and lower activity was found in the overlap alpha 23-38/alpha 34-49/alpha 45-60 and in peptide alpha 194-210. In addition, peptides alpha 100-115 and alpha 56-71 showed strong and medium binding activities to Eb, but low activity to Cot, whereas peptide alpha 1-16 exhibited low binding to Cot and no binding to Eb. Comparison with previous studies indicated that, for human AChR, the binding regions of short and long neurotoxins were essentially the same. The finding that the region within residues alpha 122-138 of both human and Torpedo AChR possessed the highest binding activity with short neurotoxins indicated that this region constitutes a universal binding site for long and short neurotoxins on AChR from various species.

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