Probing the Structure and Function of theEscherichia coliDNA Alkylation Repair AlkB Protein through Chemical Cross-Linking

2003 ◽  
Vol 125 (29) ◽  
pp. 8730-8731 ◽  
Author(s):  
Yukiko Mishina ◽  
Chuan He
Keyword(s):  
Structure And Function ◽  
Cross Linking ◽  
And Function ◽  
Chemical Cross Linking

Impact of Chemical Cross-Linking on Protein Structure and Function

2018 ◽  
Vol 90 (2) ◽  
pp. 1104-1113 ◽  
Author(s):  
Daniel Rozbeský ◽  
Michal Rosůlek ◽  
Zdeněk Kukačka ◽  
Josef Chmelík ◽  
Petr Man ◽  
...  
Keyword(s):  
Protein Structure ◽  
Structure And Function ◽  
Cross Linking ◽  
Protein Structure And Function ◽  
And Function ◽  
Chemical Cross Linking

scholarly journals Overexpression of cofilin stimulates bundling of actin filaments, membrane ruffling, and cell movement in Dictyostelium.

1996 ◽  
Vol 132 (3) ◽  
pp. 335-344 ◽  
Author(s):  
H Aizawa ◽  
K Sutoh ◽  
I Yahara
Keyword(s):  
Actin Filaments ◽  
Cell Movement ◽  
Structure And Function ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Filamentous Actin ◽  
Membrane Ruffling ◽  
And Function

Cofilin is a low molecular weight actin-modulating protein whose structure and function are conserved among eucaryotes. Cofilin exhibits in vitro both a monomeric actin-sequestering activity and a filamentous actin-severing activity. To investigate in vivo functions of cofilin, cofilin was overexpressed in Dictyostelium discoideum cells. An increase in the content of D. discoideum cofilin (d-cofilin) by sevenfold induced a co-overproduction of actin by threefold. In cells over-expressing d-cofilin, the amount of filamentous actin but not that of monomeric actin was increased. Overexpressed d-cofilin co-sedimented with actin filaments, suggesting that the sequestering activity of d-cofilin is weak in vivo. The overexpression of d-cofilin increased actin bundles just beneath ruffling membranes where d-cofilin was co-localized. The overexpression of d-cofilin also stimulated cell movement as well as membrane ruffling. We have demonstrated in vitro that d-cofilin transformed latticework of actin filaments cross-linked by alpha-actinin into bundles probably by severing the filaments. D. discoideum cofilin may sever actin filaments in vivo and induce bundling of the filaments in the presence of cross-linking proteins so as to generate contractile systems involved in membrane ruffling and cell movement.

scholarly journals Studies on the basis for the properties of fibrin produced from fibrinogen-containing γ′ chains

Blood ◽  
2005 ◽  
Vol 106 (8) ◽  
pp. 2730-2736 ◽  
Author(s):  
Kevin R. Siebenlist ◽  
Michael W. Mosesson ◽  
Irene Hernandez ◽  
Leslie A. Bush ◽  
Enrico Di Cera ◽  
...  
Keyword(s):  
Network Structure ◽  
Factor Xiii ◽  
Structure And Function ◽  
Catalytic Site ◽  
Cross Linking ◽  
Terminal Sequence ◽  
Human Fibrinogen ◽  
Delayed Release ◽  
Functional Features ◽  
And Function

AbstractHuman fibrinogen 1 is homodimeric with respect to its γ chains (`γA-γA'), whereas fibrinogen 2 molecules each contain one γA (γA1-411V) and one γ′ chain, which differ by containing a unique C-terminal sequence from γ′408 to 427L that binds thrombin and factor XIII. We investigated the structural and functional features of these fibrins and made several observations. First, thrombin-treated fibrinogen 2 produced finer, more branched clot networks than did fibrin 1. These known differences in network structure were attributable to delayed release of fibrinopeptide (FP) A from fibrinogen 2 by thrombin, which in turn was likely caused by allosteric changes at the thrombin catalytic site induced by thrombin exosite 2 binding to the γ′ chains. Second, cross-linking of fibrin γ chains was virtually the same for both types of fibrin. Third, the acceleratory effect of fibrin on thrombin-mediated XIII activation was more prominent with fibrin 1 than with fibrin 2, and this was also attributable to allosteric changes at the catalytic site induced by thrombin binding to γ′ chains. Fourth, fibrinolysis of fibrin 2 was delayed compared with fibrin 1. Altogether, differences between the structure and function of fibrins 1 and 2 are attributable to the effects of thrombin binding to γ′ chains.

scholarly journals Corneal cross-linking methods and outcomes: A review

2016 ◽  
Vol 75 (1) ◽  
Author(s):  
Deanne Lee Nicholas ◽  
Wayne D.H. Gillian
Keyword(s):  
Mechanical Properties ◽  
Treatment Method ◽  
Structure And Function ◽  
Alternative Methods ◽  
Cross Linking ◽  
Invasive Treatment ◽  
Beneficial Effects ◽  
Ocular Structure ◽  
Corneal Structure ◽  
And Function

The prevalence of corneal ectasias such as keratoconus has been widely documented. Keratoconus may lead to detrimental changes in visual acuity, which can often be corrected in the early stages but requires more invasive treatment as the condition progresses. Corneal cross-linking has become a treatment method of choice in early keratoconic patients and is used to stabilise the condition and prevent further progression of the disease. The principle behind this procedure is the creation of additional bonds within the corneal structure in order to enhance its mechanical properties and thereafter halt the progression of the condition. There are disagreements within the literature as to how these procedures can be performed, and there are various alternative methods. It can be concluded that corneal cross-linking is an effective treatment method for keratoconus and has been shown to produce various beneficial effects in terms of ocular structure and function.

scholarly journals Corneal Sensitivity in Keratoconus: A Review of the Literature

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Leopoldo Spadea ◽  
Serena Salvatore ◽  
Enzo Maria Vingolo
Keyword(s):  
Structure And Function ◽  
Eye Disease ◽  
Cross Linking ◽  
Review Of The Literature ◽  
Corneal Sensitivity ◽  
Corneal Nerves ◽  
Corneal Structure ◽  
Conjunctival Cells ◽  
Sensitivity Changes ◽  
And Function

Corneal sensitivity has recently received much attention given the crucial role the corneal nerves play in maintaining normal corneal structure and function. An increased understanding of the corneal sensitivity and dry eye disease in keratoconus, including alterations of the conjunctival cells, may help explain the pathogenesis of this disorder. There is histological evidence of the involvement of corneal nerves in the pathology of keratoconus and it has been suggested that this plays a role in the pathophysiological features and progression of the disease. In this review, the impaired corneal sensitivity found on keratoconus and corneal sensitivity changes after cross-linking performed in patients with keratoconus are reported.

Chemical Cross-linking and Mass Spectrometry for the Structural Analysis of Protein Assemblies

2013 ◽  
Vol 66 (7) ◽  
pp. 749 ◽  
Author(s):  
Antonio N. Calabrese ◽  
Tara L. Pukala
Keyword(s):  
Mass Spectrometry ◽  
Structural Biology ◽  
Structural Information ◽  
Cross Linking ◽  
Spectrometric Analysis ◽  
Protein Assemblies ◽  
Cellular Functions ◽  
The Past ◽  
And Function ◽  
Chemical Cross Linking

Cellular functions are performed and regulated at a molecular level by the coordinated action of intricate protein assemblies, and hence the study of protein folding, structure, and interactions is vital to the appreciation and understanding of complex biological problems. In the past decade, continued development of chemical cross-linking methodologies combined with mass spectrometry has seen this approach develop to enable detailed structural information to be elucidated for protein assemblies often intractable by traditional structural biology methods. In this review article, we describe recent advances in reagent design, cross-linking protocols, mass spectrometric analysis, and incorporation of cross-linking constraints into structural models, which are contributing to overcoming the intrinsic challenges of the cross-linking method. We also highlight pioneering applications of chemical cross-linking mass spectrometry approaches to the study of structure and function of protein assemblies.

scholarly journals Mechanism of Tissue Factor Activation on HL-60 Cells

Blood ◽  
1997 ◽  
Vol 89 (9) ◽  
pp. 3270-3276 ◽  
Author(s):  
Ronald R. Bach ◽  
Charles F. Moldow
Keyword(s):  
Binding Site ◽  
Tissue Factor ◽  
Quaternary Structure ◽  
Factor Viia ◽  
Calcium Ionophore ◽  
Structure And Function ◽  
Cross Linking ◽  
Substrate Binding Site ◽  
Pseudosubstrate Inhibitors ◽  
And Function

AbstractTissue factor (TF ) procoagulant activity (PCA) on the surface of intact HL-60 cells is encrypted. This latent TF PCA was activated by exposing the cells to ionomycin, a calcium ionophore. Within seconds an increase in TF PCA of greater than 100-fold was observed. The ionomycin effect was blocked by pretreating the cells with calmidazolium, a calmodulin inhibitor. Changes in TF structure and function, coincident with the ionophore-induced increase in TF PCA, were identified. TF-factor VIIa complexes formed on both untreated and ionophore-treated cells, but pseudosubstrate inhibitors only bound to TF-factor VIIa on the ionophore-treated cells. TF PCA was inhibited by reacting cells with sulfosuccinimidyl-6-(biotinamido)hexanoate, and the rate of this reaction increased twofold after cells were exposed to ionomycin. When proteins on the surface of untreated cells, expressing minimal TF PCA, were cross-linked with 3-3′-dithiobis(sulfosuccinimidylpropionate), cross-linked TF dimers were produced. TF cross-linking was prevented by first treating the cells with ionomycin. These results suggest a mechanism for the ionomycin-induced increase in TF PCA. TF activation appears to be a calmodulin-dependent process, which exposes an essential macromolecular substrate binding site on TF, possibly as the result of a change in TF quaternary structure.

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