scholarly journals ADP-induced platelet aggregation depends on the conformation or availability of the terminal gamma chain sequence of fibrinogen. Study of the reactivity of fibrinogen Paris 1

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 558-563 ◽  
Author(s):  
MH Denninger ◽  
M Jandrot-Perrus ◽  
J Elion ◽  
O Bertrand ◽  
GA Homandberg ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
High Performance ◽  
Cross Linking ◽  
Gamma Chain ◽  
Carboxy Terminal Region ◽  
Chain Polymerization ◽  
Triethylene Tetramine ◽  
Terminal Structure ◽  
Carboxy Terminal ◽  
Peptide Insertion

Abstract Fibrinogen Paris I contains a mutant gamma chain that is longer than the normal chain, resulting in altered fibrin polymerization and cross- linking. Because these functions involve the carboxy-terminal region of the gamma chain, we decided to determine whether fibrinogen Paris I or the isolated Paris I gamma chain supports normal ADP-induced platelet aggregation, a function that requires the ultimate 12 residues of the normal gamma chain (400 through 411). Aggregation of ADP-stimulated normal platelets was defective with fibrinogen Paris I and markedly depressed with the gamma Paris I chain. These findings prompted us to characterize the carboxy-terminal structure of the region of the gamma Paris I chain responsible for this activity. The carboxy-terminal cyanogen bromide (CNBr) peptide of the normal gamma chain (385 through 411) or that from gamma Paris I was isolated by differential adsorption to triethylene-tetramine resin or by reverse-phase high-performance liquid chromatography (HPLC). The CNBr peptide from the Paris I gamma chain was identical to that of the normal gamma chain in its retention time on HPLC, its amino acid composition, and its sequence. Thus, the primary structure of the gamma Paris I chain from residue 384 through 411 is normal, indicating that a peptide insertion has occurred upstream from residue 384, resulting in an impairment of those physiologic functions attributable to the carboxy-terminal end of the gamma chain from position 384 (ie, cross-linking, ADP-induced platelet aggregation, and at least a portion of the gamma chain polymerization site). These observations demonstrate that the gamma chain platelet recognition site in the fibrinogen molecule is necessary but not alone sufficient to support normal ADP-induced platelet aggregation. There appears to be an additional requirement for normal conformation of the gamma chain or availability of its terminal sequence during the interaction of fibrinogen with platelets.

scholarly journals ADP-induced platelet aggregation depends on the conformation or availability of the terminal gamma chain sequence of fibrinogen. Study of the reactivity of fibrinogen Paris 1

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 558-563
Author(s):  
MH Denninger ◽  
M Jandrot-Perrus ◽  
J Elion ◽  
O Bertrand ◽  
GA Homandberg ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
High Performance ◽  
Cross Linking ◽  
Gamma Chain ◽  
Carboxy Terminal Region ◽  
Chain Polymerization ◽  
Triethylene Tetramine ◽  
Terminal Structure ◽  
Carboxy Terminal ◽  
Peptide Insertion

Fibrinogen Paris I contains a mutant gamma chain that is longer than the normal chain, resulting in altered fibrin polymerization and cross- linking. Because these functions involve the carboxy-terminal region of the gamma chain, we decided to determine whether fibrinogen Paris I or the isolated Paris I gamma chain supports normal ADP-induced platelet aggregation, a function that requires the ultimate 12 residues of the normal gamma chain (400 through 411). Aggregation of ADP-stimulated normal platelets was defective with fibrinogen Paris I and markedly depressed with the gamma Paris I chain. These findings prompted us to characterize the carboxy-terminal structure of the region of the gamma Paris I chain responsible for this activity. The carboxy-terminal cyanogen bromide (CNBr) peptide of the normal gamma chain (385 through 411) or that from gamma Paris I was isolated by differential adsorption to triethylene-tetramine resin or by reverse-phase high-performance liquid chromatography (HPLC). The CNBr peptide from the Paris I gamma chain was identical to that of the normal gamma chain in its retention time on HPLC, its amino acid composition, and its sequence. Thus, the primary structure of the gamma Paris I chain from residue 384 through 411 is normal, indicating that a peptide insertion has occurred upstream from residue 384, resulting in an impairment of those physiologic functions attributable to the carboxy-terminal end of the gamma chain from position 384 (ie, cross-linking, ADP-induced platelet aggregation, and at least a portion of the gamma chain polymerization site). These observations demonstrate that the gamma chain platelet recognition site in the fibrinogen molecule is necessary but not alone sufficient to support normal ADP-induced platelet aggregation. There appears to be an additional requirement for normal conformation of the gamma chain or availability of its terminal sequence during the interaction of fibrinogen with platelets.

scholarly journals Characterization of the gamma chain platelet binding site on fibrinogen fragment D

Blood ◽  
1992 ◽  
Vol 79 (10) ◽  
pp. 2643-2648 ◽  
Author(s):  
NE Kirschbaum ◽  
MW Mosesson ◽  
DL Amrani
Keyword(s):  
Platelet Aggregation ◽  
Binding Site ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Gamma Chain ◽  
Platelet Surface ◽  
Fibrinogen Binding ◽  
Platelet Binding ◽  
Chain Sequence ◽  
Carboxy Terminal

Abstract Glycoprotein (GP) IIb/IIIa on adenosine diphosphate (ADP)-activated human platelets interacts with specific sites on the fibrinogen molecule leading to aggregation. We characterized the platelet-binding site on the gamma chains of fibrinogen using plasmic fragments D gamma A and D gamma'. Fragment D gamma A, which contains the carboxy terminal gamma A400–411 platelet-binding sequence (HHLGGAKQAGDV), was 70-fold more active than the synthetic gamma A400–411 peptide in inhibiting ADP- induced platelet aggregation. Fragment D gamma A inhibited fibrinogen binding and also bound directly to ADP-activated platelets. The Kd values determined for fibrinogen and fragment D gamma A binding were 0.55 mumol/L and 1.2 mumol/L, respectively. In contrast, fragment D gamma', which differs from fragment D gamma A with respect to its gamma chain sequence from position 408 to the COOH-terminus at position 427, did not inhibit platelet aggregation or fibrinogen binding, and did not bind directly to the platelet surface. Denaturation of fragment D gamma A with guanidine-HCl caused a loss of inhibitory activity in platelet aggregation assays. These data indicate that the native conformation of the gamma chain platelet-binding site on fibrinogen is important for optimal binding to GPIIb/IIIa.

scholarly journals Characterization of the gamma chain platelet binding site on fibrinogen fragment D

Blood ◽  
1992 ◽  
Vol 79 (10) ◽  
pp. 2643-2648 ◽  
Author(s):  
NE Kirschbaum ◽  
MW Mosesson ◽  
DL Amrani
Keyword(s):  
Platelet Aggregation ◽  
Binding Site ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Gamma Chain ◽  
Platelet Surface ◽  
Fibrinogen Binding ◽  
Platelet Binding ◽  
Chain Sequence ◽  
Carboxy Terminal

Glycoprotein (GP) IIb/IIIa on adenosine diphosphate (ADP)-activated human platelets interacts with specific sites on the fibrinogen molecule leading to aggregation. We characterized the platelet-binding site on the gamma chains of fibrinogen using plasmic fragments D gamma A and D gamma'. Fragment D gamma A, which contains the carboxy terminal gamma A400–411 platelet-binding sequence (HHLGGAKQAGDV), was 70-fold more active than the synthetic gamma A400–411 peptide in inhibiting ADP- induced platelet aggregation. Fragment D gamma A inhibited fibrinogen binding and also bound directly to ADP-activated platelets. The Kd values determined for fibrinogen and fragment D gamma A binding were 0.55 mumol/L and 1.2 mumol/L, respectively. In contrast, fragment D gamma', which differs from fragment D gamma A with respect to its gamma chain sequence from position 408 to the COOH-terminus at position 427, did not inhibit platelet aggregation or fibrinogen binding, and did not bind directly to the platelet surface. Denaturation of fragment D gamma A with guanidine-HCl caused a loss of inhibitory activity in platelet aggregation assays. These data indicate that the native conformation of the gamma chain platelet-binding site on fibrinogen is important for optimal binding to GPIIb/IIIa.

Inhibition of Platelet Adhesion to Fibrin(ogen) in Flowing Whole Blood by Arg-Gly-Asp and Fibrinogen γ-Chain Carboxy Terminal Peptides

1992 ◽  
Vol 68 (06) ◽  
pp. 694-700 ◽  
Author(s):  
Roy R Hantgan ◽  
Silvia C Endenburg ◽  
I Cavero ◽  
Gérard Marguerie ◽  
André Uzan ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Integrin Receptor ◽  
Shear Rates ◽  
Perfusion Chamber ◽  
Receptor Recognition ◽  
Adhesive Interactions ◽  
Coated Surfaces ◽  
Carboxy Terminal

SummaryWe have employed synthetic peptides with sequences corresponding to the integrin receptor-recognition regions of fibrinogen as inhibitors of platelet aggregation and adhesion to fibrinogen-and fibrin-coated surfaces in flowing whole blood, using a rectangular perfusion chamber at wall shear rates of 300 s–1 and 1,300 s–1. D-RGDW caused substantial inhibition of platelet aggregation and adhesion to fibrinogen and fibrin at both shear rates, although it was least effective at blocking platelet adhesion to fibrin at 300 s–1. RGDS was a weaker inhibitor, and produced a biphasic dose-response curve; SDRG was inactive. HHLGGAK-QAGDV partially inhibited platelet aggregation and adhesion to fibrin(ogen) at both shear rates. These results support the identification of an RGD-specific receptor, most likely the platelet integrin glycoprotein IIb: III a, as the primary receptor responsible for platelet: fibrin(ogen) adhesive interactions under flow conditions, and indicate that platelet adhesion to surface bound fibrin(ogen) is stabilized by multivalent receptor-ligand contacts.

The Ability of Fibrinogens, FI and FII, to Support ADP- Induced Platelet Aggregation

1983 ◽  
Vol 50 (02) ◽  
pp. 527-529 ◽  
Author(s):  
H M Phillips ◽  
A Mansouri ◽  
C A Perry
Keyword(s):  
Platelet Aggregation ◽  
Terminal Portion ◽  
Hepes Buffer ◽  
Carboxy Terminal

SummaryFibrinogen plays an integral part in ADP-induced platelet aggregation. Controversy exists in regard to the role of the carboxy termini of fibrinogen Aa chains in this reaction. We have attempted to clarify this problem in view of the availability of a highly purified FII fibrinogen fraction. Kabi fibrinogen or its purified fractions FI, FII and FIII-IV-V were added to washed platelets in the presence of Tyrode-HEPES buffer pH 7.4. Aggregation was initiated by the addition of calcium and ADP. These fibrinogen fractions equally promoted ADP-induced platelet aggregation. The major difference among these fractions is in their Aα chains. The FI fraction contains intact Aα chains while FII and FIH-IV-V fractions have one and two partially degraded Aα chains at the carboxy terminal portion respectively. We conclude that the carboxy terminal portion of the Aα chain does not play an important role in promoting ADP-induced platelet aggregation.

Bone turnover marker reference intervals in young females

2016 ◽  
Vol 54 (4) ◽  
pp. 438-447 ◽  
Author(s):  
Emma T Callegari ◽  
Alexandra Gorelik ◽  
Suzanne M Garland ◽  
Cherie Y Chiang ◽  
John D Wark
Keyword(s):  
Bone Turnover ◽  
Bone Turnover Markers ◽  
Bone Turnover Marker ◽  
Reference Intervals ◽  
Cross Linking ◽  
Young Females ◽  
Procollagen Type ◽  
Turnover Markers ◽  
Carboxy Terminal

Background The use of bone turnover markers in clinical practice and research in younger people is limited by the lack of normative data and understanding of common causes of variation in bone turnover marker values in this demographic. To appropriately interpret bone turnover markers, robust reference intervals specific to age, development and sex are necessary. This study aimed to determine reference intervals of bone turnover markers in females aged 16–25 years participating in the Safe-D study. Methods Participants were recruited through social networking site Facebook and were asked to complete an extensive, online questionnaire and attend a site visit. Participants were tested for serum carboxy-terminal cross-linking telopeptide of type 1 collagen and total procollagen type 1 N-propeptide using the Roche Elecsys automated analyser. Reference intervals were determined using the 2.5th to 97.5th percentiles of normalized bone turnover marker values. Results Of 406 participants, 149 were excluded due to medical conditions or medication use (except hormonal contraception) which may affect bone metabolism. In the remaining 257 participants, the reference interval was 230–1000 ng/L for serum carboxy-terminal cross-linking telopeptide of type 1 collagen and 27–131  µg/L for procollagen type 1 N-propeptide. Both marker concentrations were inversely correlated with age and oral contraceptive pill use. Therefore, intervals specific to these variables were calculated. Conclusions We defined robust reference intervals for cross-linking telopeptide of type 1 collagen and procollagen type 1 N-propeptide in young females grouped by age and contraceptive pill use. We examined bone turnover markers’ relationship with several lifestyle, clinical and demographic factors. Our normative intervals should aid interpretation of bone turnover markers in young females particularly in those aged 16 to 19 years where reference intervals are currently provisional.

scholarly journals Hyperbranched polyamide modified graphene oxide-reinforced polyurethane nanocomposites with enhanced mechanical properties

RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14484-14494
Author(s):  
Yahao Liu ◽  
Jian Zheng ◽  
Xiao Zhang ◽  
Yongqiang Du ◽  
Guibo Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
High Performance ◽  
Cross Linking ◽  
Elongation At Break ◽  
Modified Graphene Oxide ◽  
High Performance Composite ◽  
Modified Graphene ◽  
Polyurethane Nanocomposites ◽  
Hyperbranched Polyamide

We successfully modified graphene oxide with amino-terminated hyperbranched polyamide (HGO), and obtained a high-performance composite with enhanced strength and elongation at break via cross-linking hydroxyl-terminated polybutadiene chains with HGO.

scholarly journals The Carboxy-Terminal Region of apoA-I Is Required for the ABCA1-Dependent Formation of α-HDL But Not Preβ-HDL Particles in Vivo†

Biochemistry ◽  
2007 ◽  
Vol 46 (19) ◽  
pp. 5697-5708 ◽  
Author(s):  
Angeliki Chroni ◽  
Georgios Koukos ◽  
Adelina Duka ◽  
Vassilis I. Zannis
Keyword(s):  
Terminal Region ◽  
Carboxy Terminal Region ◽  
Carboxy Terminal

High performance anion exchange membranes obtained through graft architecture and rational cross-linking

2014 ◽  
Vol 470 ◽  
pp. 229-236 ◽  
Author(s):  
Jin Ran ◽  
Liang Wu ◽  
Qianqian Ge ◽  
Yaoyao Chen ◽  
Tongwen Xu
Keyword(s):  
Anion Exchange ◽  
High Performance ◽  
Cross Linking ◽  
Anion Exchange Membranes

Surface and Adhesive Properties of Low-Density Polyethylene after Radiation Cross-Linking

2014 ◽  
Vol 606 ◽  
pp. 265-268 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Performance ◽  
Chemical Properties ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Low Density ◽  
X Rays ◽  
Radiation Processing ◽  
Adhesive Properties ◽  
Γ Rays

Radiation cross-linking gives inexpensive commodity plastics and technical plastics the mechanical, thermal, and chemical properties of high-performance plastic. This upgrading of the plastics enables them to be used in conditions which they would not be able to with stand otherwise. The irradiation cross-linking of thermoplastic materials via electron beam or cobalt 60 (gammy rays) is performed separately, after processing. Generally, ionizing radiation includes accelerated electrons, gamma rays and X-rays. Radiation processing with an electron beam offers several distinct advantages when compared with other radiation sources, particularly γ-rays and x-rays. The process is very fast, clean and can be controlled with much precision. There is no permanent radioactivity since the machine can be switched off. In contrast to γ-rays and x-rays, the electron beam can steered relatively easily, thus allowing irradiation of a variety of physical shapes. The energy-rich beta rays trigger chemical reactions in the plastics which results in networking of molecules (comparable to the vulcanization of rubbers which has been in industrial use for so long). The energy from the rays is absorbed by the material and cleavage of chemical bonds takes place. This releases free radicals which in next phase from desired molecular bonds. This article describes the effect of radiation cross-linking on the surface and adhesive properties of low-density polyethylene.

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