scholarly journals Crystal Structure of the Complex mAb 17.2 and the C-Terminal Region of Trypanosoma cruzi P2β Protein: Implications in Cross-Reactivity

2011 ◽  
Vol 5 (11) ◽  
pp. e1375 ◽  
Author(s):  
Juan Carlos Pizarro ◽  
Ginette Boulot ◽  
Graham A. Bentley ◽  
Karina A. Gómez ◽  
Johan Hoebeke ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Trypanosoma Cruzi ◽  
Cross Reactivity ◽  
Terminal Region

scholarly journals KCTD proteins as Cullin3 E3 Ligase adapters

2014 ◽  
Vol 70 (a1) ◽  
pp. C305-C305
Author(s):  
Alan Ji ◽  
Gilbert Privé
Keyword(s):  
Crystal Structure ◽  
Structural Characterization ◽  
Dissociation Constants ◽  
E3 Ligase ◽  
Terminal Region ◽  
Btb Domain ◽  
Substrate Protein ◽  
Ubiquitin E3 Ligase ◽  
Ubiquitin Moiety

Cullin3 (Cul3) is an ubiquitin E3 ligase responsible for catalyzing the transfer of an ubiquitin moiety from an E2 enzyme to a target substrate protein. The C-terminal region of Cul3 binds RBX1/E2-ubiquitin, while, the N-terminal region interacts with various BTB domain proteins which serve as substrate adaptors. Previously, our group determined the crystal structures of the homodimeric BTB proteins SPOP and KLHL3 in complex with the N-terminal domain of Cul3, revealing the determinants responsible for the BTB/Cul3 interaction [1, 2]. A second class of BTB-domain containing proteins, the KCTD proteins, are also Cul3 substrate adaptors but these do not share many of the previously determined features for Cul3 binding. Furthermore, KCTD proteins form homotetramers and homopentamers via BTB oligomerization rather than the previously described homodimers. Despite these differences, many KCTD proteins interact with Cul3 with dissociation constants of approximately 50 nM. While the target substrates for many of the KCTD/Cul3 E3 ligase complexes are unknown, recent studies have implicated the GABAβ2 receptor as an interactor of KCTD 8, 12, 12b and 16. Here, we report the pentameric crystal structure of the KCTD9 BTB domain and our progress on the structural characterization of Cul3/KCTD/substrate complexes.

scholarly journals Characterization of antral gastrin cells with region-specific antisera.

1977 ◽  
Vol 25 (12) ◽  
pp. 1317-1321 ◽  
Author(s):  
L I Larsson ◽  
J F Rehfeld
Keyword(s):  
Cross Reactivity ◽  
Terminal Region ◽  
Gastrin Cells ◽  
Related Peptide ◽  
Specific Antisera

A number of gastrin antisera, which in radioimmunoassay systems showed no or negligible cross-reactivity towards the structurally and functionally related peptide cholecystokinin were found to react with both gastrin and cholecystokinin cells when used for immunocytochemistry. This discrepancy was shown to be due either to reactivity against a COOH-terminal region common to gastrin and cholecystokinin or to the occurrence of heterogenous antibody populations in the antisera. By differential absorptions the latter type of antisera could be rendered specific for gastrin. Antisera reactive against the NH2-terminal, middle or COOH-terminal regions of human heptadecapeptide gastrin were prepared and together with a specific cholecystokinin antiserum used for the characterization of antral gastrin cells of different species. The results indicate that only the COOH-terminal region of gastrin is conserved during evolution.

scholarly journals Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera

1989 ◽  
Vol 84 (3) ◽  
pp. 309-314 ◽  
Author(s):  
M. G. Morgado ◽  
J. Ivo-dos-Santos ◽  
R. T. Pinho ◽  
E. Argüelles ◽  
J. M. Rezende ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Trypanosoma Cruzi ◽  
Western Blot ◽  
Chagas Disease ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
The Other ◽  
Molecular Weights ◽  
Human Visceral Leishmaniasis ◽  
Human Immune

Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-reactivity was observed when sera from human visceral leishmaniasis were used, while only a slight cross-reaction was observed with sera from tegumentar leishmaniasis. On the other hand, 10 polypeptidesspecifically reacting with sera from Chagas' disease patients were identified. Among them, the antigens with molecular weights of 46 kDa and 25 kDa reacted with all sera teste and may be good candidates for specific immunodiagnosis of Chagas' disease.

Crystal structure of Q4D6Q6, a conserved kinetoplastid-specific protein from Trypanosoma cruzi

2020 ◽  
Vol 211 (2) ◽  
pp. 107536
Author(s):  
Éverton Dias D'Andréa ◽  
Yvette Roske ◽  
Guilherme A.P. de Oliveira ◽  
Nils Cremer ◽  
Anne Diehl ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Trypanosoma Cruzi ◽  
Specific Protein

scholarly journals The C-terminal region of human plasma fetuin-B is dispensable for the raised-elephant-trunk mechanism of inhibition of astacin metallopeptidases

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tibisay Guevara ◽  
Hagen Körschgen ◽  
Anna Cuppari ◽  
Carlo Schmitz ◽  
Michael Kuske ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Physiological Role ◽  
Zinc Ion ◽  
Terminal Region ◽  
Elephant Trunk ◽  
Regular Secondary Structure ◽  
Mechanism Of Inhibition ◽  
Human Fertility ◽  
Complex Crystal Structure

Abstract Human fetuin-B plays a key physiological role in human fertility through its inhibitory action on ovastacin, a member of the astacin family of metallopeptidases. The inhibitor consists of tandem cystatin-like domains (CY1 and CY2), which are connected by a linker containing a “CPDCP-trunk” and followed by a C-terminal region (CTR) void of regular secondary structure. Here, we solved the crystal structure of the complex of the inhibitor with archetypal astacin from crayfish, which is a useful model of human ovastacin. Two hairpins from CY2, the linker, and the tip of the “legumain-binding loop” of CY1 inhibit crayfish astacin following the “raised-elephant-trunk mechanism” recently reported for mouse fetuin-B. This inhibition is exerted by blocking active-site cleft sub-sites upstream and downstream of the catalytic zinc ion, but not those flanking the scissile bond. However, contrary to the mouse complex, which was obtained with fetuin-B nicked at a single site but otherwise intact, most of the CTR was proteolytically removed during crystallization of the human complex. Moreover, the two complexes present in the crystallographic asymmetric unit diverged in the relative arrangement of CY1 and CY2, while the two complexes found for the mouse complex crystal structure were equivalent. Biochemical studies in vitro confirmed the differential cleavage susceptibility of human and mouse fetuin-B in front of crayfish astacin and revealed that the cleaved human inhibitor blocks crayfish astacin and human meprin α and β only slightly less potently than the intact variant. Therefore, the CTR of animal fetuin-B orthologs may have a function in maintaining a particular relative orientation of CY1 and CY2 that nonetheless is dispensable for peptidase inhibition.

High-resolution crystal structure reveals a HEPN domain at the C-terminal region of S. cerevisiae RNA endonuclease Swt1

2014 ◽  
Vol 453 (4) ◽  
pp. 826-832 ◽  
Author(s):  
Shuxia Peng ◽  
Ke Zhou ◽  
Wenjia Wang ◽  
Zengqiang Gao ◽  
Yuhui Dong ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Terminal Region ◽  
Rna Endonuclease

scholarly journals Evaluation of Serological Tests To Identify Trypanosoma cruzi Infection in Humans and Determine Cross-Reactivity with Trypanosoma rangeli and Leishmania spp.

2007 ◽  
Vol 14 (8) ◽  
pp. 1045-1049 ◽  
Author(s):  
Zuleima C. Caballero ◽  
Octavio E. Sousa ◽  
Waldelania P. Marques ◽  
Amadeo Saez-Alquezar ◽  
Eufrosina S. Umezawa
Keyword(s):  
Trypanosoma Cruzi ◽  
Synthetic Peptides ◽  
Cross Reactivity ◽  
Reference Test ◽  
Trypanosoma Rangeli ◽  
Serological Tests ◽  
Western Blot Assay ◽  
Leishmania Spp ◽  
Cruzi Infection ◽  
Secreted Antigens

ABSTRACT Five commercially available enzyme-linked immunosorbent assays (ELISAs), one in-house ELISA, and two hemagglutination assays were evaluated to determine their diagnostic accuracy for Chagas' disease in two studies. In study 1, ELISA kits showed 100% sensitivity, but specificities ranged from 82.84% to 100% when leishmaniasis cases were included and from 95.57% to 100% when leishmaniasis cases were excluded. Kits using recombinant antigens or synthetic peptides are more specific than those using crude extracts from Trypanosoma cruzi epimastigote forms. Kits evaluated in Panama, in study 2, showed 75% to 100% sensitivity and 97.12% to 100% specificity. These data were obtained by using a Western blot assay with T. cruzi trypomastigote excreted-secreted antigens as a reference test to confirm T. cruzi infection.

scholarly journals Recognition of pneumococcal isolates by antisera raised against PspA fragments from different clades

2008 ◽  
Vol 57 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Michelle Darrieux ◽  
Adriana T. Moreno ◽  
Daniela M. Ferreira ◽  
Fabiana C. Pimenta ◽  
Ana Lúcia S. S. de Andrade ◽  
...  
Keyword(s):  
Animal Models ◽  
Vaccine Candidate ◽  
Protein A ◽  
Surface Protein ◽  
Structural Diversity ◽  
Cross Reactivity ◽  
Terminal Region ◽  
Hybrid Protein ◽  
Pneumococcal Infections ◽  
Clade 1

Pneumococcal surface protein A (PspA) is an important vaccine candidate against pneumococcal infections, capable of inducing protection in different animal models. Based on its structural diversity, it has been suggested that a PspA-based vaccine should contain at least one fragment from each of the two major families (family 1, comprising clades 1 and 2, and family 2, comprising clades 3, 4 and 5) in order to elicit broad protection. This study analysed the recognition of a panel of 35 pneumococcal isolates bearing different PspAs by antisera raised against the N-terminal regions of PspA clades 1 to 5. The antiserum to PspA clade 4 was found to show the broadest cross-reactivity, being able to recognize pneumococcal strains containing PspAs of all clades in both families. The cross-reactivity of antibodies elicited against a PspA hybrid including the N-terminal region of clade 1 fused to a shorter and more divergent fragment (clade-defining region, or CDR) of clade 4 (PspA1–4) was also tested, and revealed a strong recognition of isolates containing clades 1, 4 and 5, and weaker reactions with clades 2 and 3. The analysis of serum reactivity against different PspA regions further revealed that the complete N-terminal region rather than just the CDR should be included in an anti-pneumococcal vaccine. A PspA-based vaccine is thus proposed to be composed of the whole N-terminal region of clades 1 and 4, which could also be expressed as a hybrid protein.

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