Topo-optical reactions of the human blood platelet membrane

Makovitzky, Josef; Bozsoky, S; László, E.

doi:10.1007/bf00489790

Cited by 9 publications

(5 citation statements)

References 30 publications

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“…1), was first used as a sensitizer in photography [3]. PCYN has also been used as a vital tool in staining leukocytes [12], in determining critical micelle concentrations [13], and as an indicator for solvent polarity due to its solvatochromic properties [14]. PCYN in aqueous solutions can undergo self-aggregation because of Van der Waals attractive forces between molecules.…”

Section: Introductionmentioning

confidence: 99%

Determination of the structure of 1,1′-diethyl-2,2′-carbocyanine iodide using NMR spectra and GIAO-HF/DFT calculations

Kim

2008

Dyes and Pigments

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Section: Introductionmentioning

confidence: 99%

Determination of the structure of 1,1′-diethyl-2,2′-carbocyanine iodide using NMR spectra and GIAO-HF/DFT calculations

Kim

2008

Dyes and Pigments

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“…The platelet membrane contains many glycoproteins that play an important role in platelet function. Sialic acid (N-acetyl neuraminic acid), a negatively charged sugar, is a regular constituent of glycoproteins and gangliosides in the outer cell membrane of mammalian cells (10)(11)(12).…”

Section: Discussionmentioning

confidence: 99%

“…Sialic acid (N-acetyl-neuraminic acid), a negatively charged sugar, is a regular constituent of glycoproteins and gangliosides in the outer cell membrane of mammalian cells (8)(9)(10). Mostly sialic acid and to a much lesser extent negatively charged amino acids like glutamate and aspartate are responsible for the cells' negative surface charge, which helps cells to keep a distance from each other due to repulsion of the same negative charges (11). Therefore, it is of particular interest to investigate the sialic acid content of platelets, which are characterized by their ability to aggregate with each other, leading to thrombus formation (12)(13)(14)(15)(16)(17).…”

mentioning

confidence: 99%

Preliminary Study Showing the Relationship Between Platelet Fibronectin, Sialic Acid, and ADP-induced Aggregation Levels in Coronary Heart Disease

Bütün¹,

Ekmekçi²,

Sönmez

et al. 2007

Clin Appl Thromb Hemost

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Several studies indicate that thrombosis plays an important role in the pathogenesis of coronary heart disease (CHD). Fibronectin is a multifunctional protein in plasma, other body fluids, and cell surface and plays an important role in platelet functions, including mediation of cell-cell and cell-surface interactions. Sialic acid is a regular constituent of glycoproteins and gangliozides in the outer cell membrane of mammalian cells. Therefore, the sialic acid content of platelets, which are characterized by their ability to aggregate with each other, can be important in leading to thrombus formation. In this study, platelet fibronectin, sialic acid-, and adenosine diphosphate (ADP)-induced platelet aggregation levels were determined in patients with CHD. Platelet sialic acid concentrations were determined by Warren's method. Platelet aggregation tests with ADP in platelet-rich plasma (PRP) were analyzed by use of an aggregometer. Platelet homogenate fibronectin levels were determined by ELISA. Total protein levels were determined by Lowry method. Our results indicate that, in patients with no vessel disease (patients with no obstructed vessel but suffering from chest pain, like angina pectoris) platelet fibronectin levels were significantly lower than the total of the other patients (patients with 1, 2, or 3 obstructed coronary vessels) (p<0.05). Sialic acid levels in patients with no vessel disease were significantly lower than the total of the patient group (p<0.05). There was significant (+) correlation between platelet aggregation, platelet fibronectin, platelet sialic acid, and severity of disease (p<0.05). Our preliminary findings suggest that, especially platelet fibronectin levels potentially represent a pathogenic factor for CHD.

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“…1) containing two C]C bonds between quinoline rings was investigated. Pinacyanol has been used as a sensitizer in photography, 33 as a vital tool in staining leukocytes 34 and as an indicator for solvent polarity. 35 Besides, in aqueous solutions this molecule undergoes hypsochromic self-aggregation.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast photoisomerization of pinacyanol: watching an excited state reaction transiting from barrier to barrierless forms

Yartsev

2016

RSC Adv.

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Photoisomerization of 1,1 0 -diethyl-2,2 0 -carbocyanine iodide (pinacyanol) in alcohols was investigated by means of femtosecond time-resolved absorption spectroscopy. Only one out of two possible types of photoisomer was found. Viscosity-dependent kinetics indicate that the excited state dynamics consist of two parts, associated with a barrier-crossing observed in the blue side of stimulated emission (SE) and the barrierless isomerization observed in the red side of SE. These two processes occur sequentially. The blue barrier SE part is characterized by a decay lifetime (s 1 , 5.2 ps in methanol) that is constant over the observed spectral region. Dependence of s 1 on solvent viscosity (h) is linear and follows Kramer's law for barrier-crossing reactions. The red barrierless part is faster and is characterized by a rise in time constants, which increases with the wavelength (s 2 l , from 0.2 to 0.6 ps for 720-1000 nm range in methanol). s 2 l depends on h as a fractional power function and follows BFO theory for barrierless photoisomerization. The overall photoisomerization rate is limited by the barrier-crossing rate, s 1 À1 . A two-state two-mode model with a saddle-type of potential energy surface (PES) was used to explain the observed spectral dynamics. Along the stretching mode it is barrierless while along the torsion mode there is a very small barrier. As a result, the PES becomes ridge-like after displacement along the stretching coordinate. Comparing pinacyanol and 1,1 0 -diethyl-2,2 0 -cyanine iodide (1122C) with similar excited state lifetimes (5.2 vs. 4.9 ps) but quite different photoisomer quantum yields (QY, 3.6% vs. 26%, respectively), we conclude that excited state PES properties play the most important role in determining when the torsion mode couples with the stretching mode, and as a result the photoisomer QY.

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Topo-optical reactions of the human blood platelet membrane

Cited by 9 publications

References 30 publications

Determination of the structure of 1,1′-diethyl-2,2′-carbocyanine iodide using NMR spectra and GIAO-HF/DFT calculations

Determination of the structure of 1,1′-diethyl-2,2′-carbocyanine iodide using NMR spectra and GIAO-HF/DFT calculations

Preliminary Study Showing the Relationship Between Platelet Fibronectin, Sialic Acid, and ADP-induced Aggregation Levels in Coronary Heart Disease

Ultrafast photoisomerization of pinacyanol: watching an excited state reaction transiting from barrier to barrierless forms

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