Pyrene-based prospective biomaterial: In vitro bioimaging, protein binding studies and detection of bilirubin and Fe3+

2019 ◽  
Vol 221 ◽  
pp. 117150 ◽  
Author(s):  
Venkatesan Srinivasan ◽  
Mariadoss Asha Jhonsi ◽  
Namasivayam Dhenadhayalan ◽  
King-Chuen Lin ◽  
Devanesan Arul Ananth ◽  
...  
Keyword(s):  
Protein Binding ◽  
Binding Studies

scholarly journals Mutational and in vitro protein-binding studies on centromere DNA from Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (12) ◽  
pp. 4522-4534 ◽  
Author(s):  
R Ng ◽  
J Carbon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Binding ◽  
In Vitro Assays ◽  
Binding Studies ◽  
Mobility Shift ◽  
Sequence Element ◽  
Sequence Elements ◽  
Mobility Shift Assay

Centromeres on chromosomes in the yeast Saccharomyces cerevisiae contain approximately 140 base pairs (bp) of DNA. The functional centromere (CEN) region contains three important sequence elements (I, PuTCACPuTG; II, 78 to 86 bp of high-AT DNA; and III, a conserved 25-bp sequence with internal bilateral symmetry). Various point mutations or deletions in the element III region have a profound effect on CEN function in vivo, indicating that this DNA region is a key protein-binding site. This has been confirmed by the use of two in vitro assays to detect binding of yeast proteins to DNA fragments containing wild-type or mutationally altered CEN3 sequences. An exonuclease III protection assay was used to demonstrate specific binding of proteins to the element III region of CEN3. In addition, a gel DNA fragment mobility shift assay was used to characterize the binding reaction parameters. Sequence element III mutations that inactivate CEN function in vivo also prevent binding of proteins in the in vitro assays. The mobility shift assay indicates that double-stranded DNAs containing sequence element III efficiently bind proteins in the absence of sequence elements I and II, although the latter sequences are essential for optimal CEN function in vivo.

Controlling the Physical Behavior and Biological Performance of Liposome Formulations Through Use of Surface Grafted Poly(ethylene Glycol)

2002 ◽  
Vol 22 (2) ◽  
pp. 225-250 ◽  
Author(s):  
C. Allen ◽  
N. Dos Santos ◽  
R. Gallagher ◽  
G.N.C. Chiu ◽  
Y. Shu ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Protein Binding ◽  
Chemical Properties ◽  
Total Serum Protein ◽  
Total Serum ◽  
Poly Ethylene Glycol ◽  
Binding Studies ◽  
Poly Ethylene

The presence of poly(ethylene glycol) (PEG) at the surface of a liposomal carrier has been clearly shown to extend the circulation lifetime of the vehicle. To this point, the extended circulation lifetime that the polymer affords has been attributed to the reduction or prevention of protein adsorption. However, there is little evidence that the presence of PEG at the surface of a vehicle actually reduces total serum protein binding. In this review we examine all aspects of PEG in order to gain a better understanding of how the polymer fulfills its biological role. The physical and chemical properties of the polymer are explored and compared to properties of other hydrophilic polymers. An evidence based assessment of several in vitro protein binding studies as well as in vivo pharmacokinetics studies involving PEG is included. The ability of PEG to prevent the self-aggregation of liposomes is considered as a possible means by which it extends circulation longevity. Also, a “dysopsonization” phenomenon where PEG actually promotes binding of certain proteins that then mask the vehicle is discussed.

Mutational and in vitro protein-binding studies on centromere DNA from Saccharomyces cerevisiae

1987 ◽  
Vol 7 (12) ◽  
pp. 4522-4534
Author(s):  
R Ng ◽  
J Carbon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Binding ◽  
In Vitro Assays ◽  
Binding Studies ◽  
Mobility Shift ◽  
Sequence Element ◽  
Sequence Elements ◽  
Mobility Shift Assay

Centromeres on chromosomes in the yeast Saccharomyces cerevisiae contain approximately 140 base pairs (bp) of DNA. The functional centromere (CEN) region contains three important sequence elements (I, PuTCACPuTG; II, 78 to 86 bp of high-AT DNA; and III, a conserved 25-bp sequence with internal bilateral symmetry). Various point mutations or deletions in the element III region have a profound effect on CEN function in vivo, indicating that this DNA region is a key protein-binding site. This has been confirmed by the use of two in vitro assays to detect binding of yeast proteins to DNA fragments containing wild-type or mutationally altered CEN3 sequences. An exonuclease III protection assay was used to demonstrate specific binding of proteins to the element III region of CEN3. In addition, a gel DNA fragment mobility shift assay was used to characterize the binding reaction parameters. Sequence element III mutations that inactivate CEN function in vivo also prevent binding of proteins in the in vitro assays. The mobility shift assay indicates that double-stranded DNAs containing sequence element III efficiently bind proteins in the absence of sequence elements I and II, although the latter sequences are essential for optimal CEN function in vivo.

Transcriptional control of the rat hepatic CYP2E1 gene

1990 ◽  
Vol 10 (9) ◽  
pp. 4495-4505
Author(s):  
T Ueno ◽  
F J Gonzalez
Keyword(s):  
Protein Binding ◽  
Protein Interactions ◽  
Transcriptional Control ◽  
Developmental Stages ◽  
Nuclear Extract ◽  
Binding Studies ◽  
Mobility Shift ◽  
Adult Rats ◽  
Cyp2e1 Gene

The rat hepatic CYP2E1 gene becomes transcriptionally activated within 1 day after birth. This activation can be mimicked by using the 5' end of the gene in a cell-free nuclear extract prepared from hepatocytes taken from rats at different developmental stages. Deletion analysis revealed that a positive element located between -127 and -89 was responsible for 90% of the in vitro transcription activity of adult liver extracts. Protein binding studies revealed that this region was operationally equivalent to the binding site for the factor HNF-1. Two other protein-binding regions were uncovered, one of which corresponded to the site for a CCAAT-binding factor NFY. The other site was a palindrome sequence unique to the CYP2E1 gene. These latter two factors did not significantly contribute to transcriptional activity in vitro and were not conserved between the rat and human CYP2E1 genes. Extracts prepared from fetal and newborn livers were transcriptionally inactive, whereas extracts from livers of 3-day-old rats were fully active toward the CYP2E1 gene. DNase I footprinting patterns indistinguishable between fetal and adult extracts were obtained for all three factors. However, gel mobility shift assays revealed a second, higher-mobility band produced by fetal and newborn liver extracts bound to the HNF-1 oligomer. UV-cross-linking studies showed that adult and fetal extracts had only a single 98-kilodalton protein that bound to this oligomer. In contrast, adult lung samples, also transcriptionally inactive toward the CYP2E1 gene, contained two proteins of slightly greater than 110 kilodaltons. These results suggest that the CYP2E1 gene is positively regulated in adult rats by HNF-1 or a protein similar in DNA-binding properties to HNF-1. The role of this factor or other protein-protein interactions in the lack of CYP2E1 transcription in fetal and newborn animals remains unclear.

scholarly journals PROTEIN BINDING STUDY OF FELODIPINE USING VALIDATED LIQUID CHROMATOGRAPHIC METHOD

2017 ◽  
pp. 134-139
Author(s):  
Swarna Vijitha ◽  
P. Rajavel ◽  
K. Udayasree
Keyword(s):  
Protein Binding ◽  
High Performance ◽  
Limit Of Detection ◽  
Binding Studies ◽  
Limit Of Quantification ◽  
Permeable Membrane ◽  
Percentage Recovery ◽  
Ich Guidelines ◽  
Liquid Chromatographic

Objective: The aim of present study was to develop and validate a new simple, easy, selective, precise, accurate reverse phase high-performance liquid chromatography for the estimation of felodipine in bulk and pharmaceutical dosage form.Methods: The separation was carried on HPLC system consisting C18 column (150 mm ×4.6 nm, 5 µm) at room temperature coupled with a phenomenixcolumn silica with flow rate 1 ml/min. The mobile phase used was methanol: acetonitrile in the ratio of 50: 50. The drug was detected using UV-visible detector at the wavelength of 230 nm and run time was 10 min.Results: The retention time was 3.138 min. Linearity was observed in the concentration range of 5-25μg/ml. The accuracy of the method was assessed by percentage recovery studies at three different levels at 80%, 100% and 120% of its working concentration. The percentage recovery of felodipine in the developed method was found to be in the ranges of from 99.81-100.00% that indicates the good accuracy of the method. The percentage % RSD of precision was found to be less than 2%. The method was validated as per ICH guidelines. The developed method was employed in in vitro protein binding studies using semi permeable membrane and performed by plotting calibration curve (peak area vs concentration) the % drug release of felodipine was calculated.Conclusion: The proposed method was found to be simple, precise, accurate and consistent. The validated parameters are statistically validated for linearity, precision and limit of detection, limit of quantification, robustness, ruggedness were concluded. 

In vitro protein binding studies with BMS-204352: lack of protein binding displacement interaction in human serum

2001 ◽  
Vol 22 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Rajesh Krishna ◽  
Ming Yao ◽  
Donna Kaczor ◽  
Nimish Vachharajani ◽  
Nuggehally R. Srinivas
Keyword(s):  
Protein Binding ◽  
Human Serum ◽  
Binding Studies ◽  
Protein Binding Displacement ◽  
Vitro Protein

scholarly journals In vitro and in vivo interactions of selected nanoparticles with rodent serum proteins and their consequences in biokinetics

2014 ◽  
Vol 5 ◽  
pp. 1699-1711 ◽  
Author(s):  
Wolfgang G Kreyling ◽  
Stefanie Fertsch-Gapp ◽  
Martin Schäffler ◽  
Blair D Johnston ◽  
Nadine Haberl ◽  
...  
Keyword(s):  
Protein Binding ◽  
Physicochemical Properties ◽  
Serum Proteins ◽  
Particle Surface ◽  
Protein Corona ◽  
Surface Modifications ◽  
Body Fluids ◽  
Binding Studies

When particles incorporated within a mammalian organism come into contact with body fluids they will bind to soluble proteins or those within cellular membranes forming what is called a protein corona. This binding process is very complex and highly dynamic due to the plethora of proteins with different affinities and fractions in different body fluids and the large variation of compounds and structures of the particle surface. Interestingly, in the case of nanoparticles (NP) this protein corona is well suited to provide a guiding vehicle of translocation within body fluids and across membranes. This NP translocation may subsequently lead to accumulation in various organs and tissues and their respective cell types that are not expected to accumulate such tiny foreign bodies. Because of this unprecedented NP accumulation, potentially adverse biological responses in tissues and cells cannot be neglected a priori but require thorough investigations. Therefore, we studied the interactions and protein binding kinetics of blood serum proteins with a number of engineered NP as a function of their physicochemical properties. Here we show by in vitro incubation tests that the binding capacity of different engineered NP (polystyrene, elemental carbon) for selected serum proteins depends strongly on the NP size and the properties of engineered surface modifications. In the following attempt, we studied systematically the effect of the size (5, 15, 80 nm) of gold spheres (AuNP), surface-modified with the same ionic ligand; as well as 5 nm AuNP with five different surface modifications on the binding to serum proteins by using proteomics analyses. We found that the binding of numerous serum proteins depended strongly on the physicochemical properties of the AuNP. These in vitro results helped us substantially in the interpretation of our numerous in vivo biokinetics studies performed in rodents using the same NP. These had shown that not only the physicochemical properties determined the AuNP translocation from the organ of intake towards blood circulation and subsequent accumulation in secondary organs and tissues but also the the transport across organ membranes depended on the route of AuNP application. Our in vitro protein binding studies support the notion that the observed differences in in vivo biokinetics are mediated by the NP protein corona and its dynamical change during AuNP translocation in fluids and across membranes within the organism.

scholarly journals Transcriptional control of the rat hepatic CYP2E1 gene.

1990 ◽  
Vol 10 (9) ◽  
pp. 4495-4505 ◽  
Author(s):  
T Ueno ◽  
F J Gonzalez
Keyword(s):  
Protein Binding ◽  
Protein Interactions ◽  
Transcriptional Control ◽  
Developmental Stages ◽  
Nuclear Extract ◽  
Binding Studies ◽  
Mobility Shift ◽  
Adult Rats ◽  
Cyp2e1 Gene

The rat hepatic CYP2E1 gene becomes transcriptionally activated within 1 day after birth. This activation can be mimicked by using the 5' end of the gene in a cell-free nuclear extract prepared from hepatocytes taken from rats at different developmental stages. Deletion analysis revealed that a positive element located between -127 and -89 was responsible for 90% of the in vitro transcription activity of adult liver extracts. Protein binding studies revealed that this region was operationally equivalent to the binding site for the factor HNF-1. Two other protein-binding regions were uncovered, one of which corresponded to the site for a CCAAT-binding factor NFY. The other site was a palindrome sequence unique to the CYP2E1 gene. These latter two factors did not significantly contribute to transcriptional activity in vitro and were not conserved between the rat and human CYP2E1 genes. Extracts prepared from fetal and newborn livers were transcriptionally inactive, whereas extracts from livers of 3-day-old rats were fully active toward the CYP2E1 gene. DNase I footprinting patterns indistinguishable between fetal and adult extracts were obtained for all three factors. However, gel mobility shift assays revealed a second, higher-mobility band produced by fetal and newborn liver extracts bound to the HNF-1 oligomer. UV-cross-linking studies showed that adult and fetal extracts had only a single 98-kilodalton protein that bound to this oligomer. In contrast, adult lung samples, also transcriptionally inactive toward the CYP2E1 gene, contained two proteins of slightly greater than 110 kilodaltons. These results suggest that the CYP2E1 gene is positively regulated in adult rats by HNF-1 or a protein similar in DNA-binding properties to HNF-1. The role of this factor or other protein-protein interactions in the lack of CYP2E1 transcription in fetal and newborn animals remains unclear.

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