scholarly journals The Poliovirus Empty Capsid Specifically Recognizes the Poliovirus Receptor and Undergoes Some, but Not All, of the Transitions Associated with Cell Entry

1998 ◽  
Vol 72 (9) ◽  
pp. 7551-7556 ◽  
Author(s):  
Ravi Basavappa ◽  
Alicia Gómez-Yafal ◽  
James M. Hogle
Keyword(s):  
Binding Sites ◽  
Cell Entry ◽  
Experimental Results ◽  
Virus Maturation ◽  
Poliovirus Receptor ◽  
Empty Capsid ◽  
Induced Changes ◽  
Mature Virus

ABSTRACT Experimental results presented here demonstrate that the poliovirus empty capsid binds with saturable character to poliovirus-susceptible cells, binds preferentially to susceptible cells, and competes with mature virus for binding sites on cells. Hence, induced changes in the structure and/or stability of the particle by RNA encapsidation and virus maturation are not necessary for recognition by receptor. In mature virus, heat-induced rearrangements mimic those induced by receptor at physiological temperatures in several important respects, namely, expulsion of VP4 and externalization of the VP1 N-terminal arm. It is shown here that in the empty capsid the VP1 N-terminal arm is externalized but the VP4 portion of VP0 is not. Thus, these two hallmark rearrangements associated with cell entry can be uncoupled.

Supramolecular self-assemblies of inverted cucurbit[7]uril with biogenic amines

2019 ◽  
Vol 43 (1) ◽  
pp. 407-412
Author(s):  
Pei-Hui Shan ◽  
Zhi-Rui Zhang ◽  
Dong Bai ◽  
Bing Bian ◽  
Zhu Tao ◽  
...  
Keyword(s):  
Biogenic Amines ◽  
Binding Affinity ◽  
Biogenic Amine ◽  
Binding Sites ◽  
Experimental Results ◽  
Binding Interactions ◽  
Strong Binding

The binding interactions between six biogenic amine guests and the iQ[7] host were investigated. The experimental results have revealed that iQ[7] shows strong binding affinity towards five of the studied biogenic amines, but not histamine, and that the binding sites are different depending on the structure of the biogenic amine.

scholarly journals Ligand-induced changes in the binding sites of proteins

2002 ◽  
Vol 18 (7) ◽  
pp. 939-948 ◽  
Author(s):  
X. Fradera ◽  
X. de la Cruz ◽  
C. H. T. P. Silva ◽  
J. L. Gelpi ◽  
F.J. Luque ◽  
...  
Keyword(s):  
Binding Sites ◽  
Induced Changes

scholarly journals Shigella applies molecular mimicry to subvert vinculin and invade host cells

2006 ◽  
Vol 175 (3) ◽  
pp. 465-475 ◽  
Author(s):  
Tina Izard ◽  
Guy Tran Van Nhieu ◽  
Philippe R.J. Bois
Keyword(s):  
Host Cell ◽  
Binding Sites ◽  
Type Iii Secretion ◽  
Molecular Mimicry ◽  
Shigella Flexneri ◽  
Cell Entry ◽  
Host Cells ◽  
General Mechanism ◽  
Host Cell Entry ◽  
Cell Spread

Shigella flexneri, the causative agent of bacillary dysentery, injects invasin proteins through a type III secretion apparatus upon contacting the host cell, which triggers pathogen internalization. The invasin IpaA is essential for S. flexneri pathogenesis and binds to the cytoskeletal protein vinculin to facilitate host cell entry. We report that IpaA harbors two vinculin-binding sites (VBSs) within its C-terminal domain that bind to and activate vinculin in a mutually exclusive fashion. Only the highest affinity C-terminal IpaA VBS is necessary for efficient entry and cell–cell spread of S. flexneri, whereas the lower affinity VBS appears to contribute to vinculin recruitment at entry foci of the pathogen. Finally, the crystal structures of vinculin in complex with the VBSs of IpaA reveal the mechanism by which IpaA subverts vinculin's functions, where S. flexneri utilizes a remarkable level of molecular mimicry of the talin–vinculin interaction to activate vinculin. Mimicry of vinculin's interactions may therefore be a general mechanism applied by pathogens to infect the host cell.

cAMP-induced changes in cAMP-binding sites on D. discoideum amebae

Cell ◽  
1977 ◽  
Vol 10 (2) ◽  
pp. 329-335 ◽  
Author(s):  
Claudette Klein ◽  
Maria Helena Juliani
Keyword(s):  
Binding Sites ◽  
Induced Changes

scholarly journals Purification and Metabolism of Rat Antithrombin III

1977 ◽  
Author(s):  
S. Okuda ◽  
M. Nakagawa ◽  
T. Okada ◽  
K. Sawada ◽  
H. Ijichi
Keyword(s):  
Free Radicals ◽  
Binding Sites ◽  
Antithrombin Iii ◽  
Binding Capacity ◽  
Experimental Results ◽  
Affinity Column ◽  
At Iii ◽  
The Difference ◽  
Rat Tissue ◽  
Sepharose 4B

The previously reported heparin sepharose affinity column has been proved to be reduced in its recovery on the repeated uses because of loose binding of ligand to sepharose. We tried to obtain the better recovery of antithrombin III (AT-III) using four different affinity columns of CNBr activated sepharose 4B, AH-sepharose 4B, CH-sepharose 4B, and Epoxy activated sepharose 6B. 3H-labeled heparin was used to check its binding capacity to sepharose gels. Binding of heparin to gel surface was found to be tight in AH-sepharose 4B, CH-sepharose 4B, and Epoxy activated sepharose 6B because of the difference of the binding sites of heparin free radicals but their recovery and purity of AT-III were poor.According to this experimental results, CNBr activated sepharose 4B was used for the purification of rat tissue AT-III and the metabolism of AT-III was investigated from the stand point of 14C-glycine. incorporation into AT-III fractions. 14C radioactivity in the tissue AT-III fractions were observed immediately after injection and reached to the maximum at 6 hours and appeared to be released into circulating pool in 2 hours after injection.

scholarly journals Antigenic Characterization of the HCMV gH/gL/gO and Pentamer Cell Entry Complexes Reveals Binding Sites for Potently Neutralizing Human Antibodies

2015 ◽  
Vol 11 (10) ◽  
pp. e1005230 ◽  
Author(s):  
Claudio Ciferri ◽  
Sumana Chandramouli ◽  
Alexander Leitner ◽  
Danilo Donnarumma ◽  
Michael A. Cianfrocco ◽  
...  
Keyword(s):  
Binding Sites ◽  
Cell Entry ◽  
Human Antibodies ◽  
Antigenic Characterization

Zinc induced changes in the progesterone binding properties of the human endometrium

1980 ◽  
Vol 94 (1) ◽  
pp. 99-106 ◽  
Author(s):  
F. K. Habib ◽  
S. Q. Maddy ◽  
S. R. Stitch
Keyword(s):  
Receptor Binding ◽  
Binding Sites ◽  
Metal Ion ◽  
Protein Concentration ◽  
Zinc Concentration ◽  
Inhibitory Effect ◽  
Association Constants ◽  
Scatchard Analysis ◽  
Binding Properties ◽  
Induced Changes

Abstract. The binding of progesterone to plasma and endometrial cytosol is markedly influenced by Zn++, the degree and magnitude of this influence being dependent on the concentration of the metal ion. There is a critical protein concentration (approximately 10 mg/ml) beyond which the zinc exerts either a stimulatory or inhibitory effect. Maximum increases in binding of over 60% were attained in solutions of plasma containing 30 mg of protein whereas increases of 10% were measured in cytosol specimens with 10 mg protein/ml. This metal mediated effect was however progressively diminished with increasing zinc concentration resulting finally in the return of the binding to the levels observed in the absence of added Zn++. The zinc induced inhibition was most evident in plasma and cytosol with a protein concentration less than 10 mg/ml. The magnitude of this effect was inversely proportional to the levels of protein in solution. Scatchard analysis of the the data revealed that the number of progesterone bindings sites in the receptor are affected by the presence of the metal while the association constants remained unchanged. The study also suggests that the zinc induced changes are partially reversed by dithiothreitol and EDTA. We believe that the metal interferes directly with the SH groups at the receptor binding sites.

Sign in / Sign up

Export Citation Format

Share Document