Book ChapterDOI
Quantitation of protein.
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TLDR
This chapter discusses various methods of estimating protein concentration as defined by the difference in energy between the orbital of the unexcited electron and a higher energy orbital.Abstract:
Publisher Summary This chapter discusses various methods of estimating protein concentration. Absorption spectroscopy involves the absorption of a photon by an electron. Only those photons with a certain energy level can be absorbed as defined by the difference in energy between the orbital of the unexcited electron and a higher energy orbital. The peptide bond absorbs photons below 210 nm. Because of the large number of peptide bonds in a protein, this is a highly sensitive area of the protein spectrum. Although protein conformation and some absorption by tryptophan and tyrosine residues occurs in this region, less variability between proteins is observed than at 280 nm. There is a need to avoid storing buffers in plastic containers because some plastics leach plasticizers, which absorb at ultraviolet (UV) wavelengths. Detergents can also be troublesome because many absorb UV light. If the buffer or protein solution is cold, the outside of the cuvette may need to be wiped between each reading with a lint-free wiper and the readings should be made quickly after placing the cold solution into the cuvette, because atmospheric moisture may condense on the outside of the cuvette producing an erroneously high reading.read more
Citations
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Journal ArticleDOI
Correlation of liquid chromatographic and biological assay for potency assessment of filgrastim and related impurities.
Ana Skrlin,Ela Kosor Krnic,Darko Gosak,Berislav Prester,Vladimir Mrša,Marko Vuletić,Domagoj Runac +6 more
TL;DR: Reversed phase high performance liquid chromatography could be used as an alternative for the in vitro biological assay for potency assessment of filgrastim samples and a significant correlation between experimental potency values and potency values estimated by the mathematical model was obtained.
Journal ArticleDOI
Combination of Polymer Technology and Carbon Nanotube Array for the Development of an Effective Drug Delivery System at Cellular Level
Cristina Riggio,Gianni Ciofani,Vittoria Raffa,Alfred Cuschieri,Silvestro Micera,Silvestro Micera +5 more
TL;DR: Results indicate that polymeric technology could be efficiently embedded in CNT array acting as drug delivery system at cellular level, and opens several perspectives in particular in the field of neurointerfaces, combining several functions into a single platform.
Journal ArticleDOI
A novel plasma membrane quinone reductase and NAD(P)H:quinone oxidoreductase 1 are upregulated by serum withdrawal in human promyelocytic HL-60 cells.
Nathalie Forthoffer,Consuelo Gómez-Díaz,Rosario I. Bello,M. I. Burón,Sergio F. Martín,Juan Carlos Rodríguez-Aguilera,Plácido Navas,José M. Villalba +7 more
TL;DR: It is demonstrated that upregulation of two-electron quinone reductases at the plasma membrane is a mechanism evoked by cells for defense against oxidative stress caused by serum withdrawal.
Journal ArticleDOI
Simulated gastrointestinal digestion of amaranth flour and protein isolate: Comparison of methodologies and release of antioxidant peptides.
TL;DR: The modification of digestion conditions produced only small differences in the molecular composition but did not affect the proteolysis degree and the antioxidant activity in the case of digested from protein isolate, while the presence of other components and changes in the digestion method had an impact on proteolytic, composition and antioxidant activity of flour digested.
References
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Journal Article
Protein Measurement with the Folin Phenol Reagent
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
Journal ArticleDOI
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding
TL;DR: This assay is very reproducible and rapid with the dye binding process virtually complete in approximately 2 min with good color stability for 1 hr with little or no interference from cations such as sodium or potassium nor from carbohydrates such as sucrose.
PatentDOI
Measurement of protein using bicinchoninic acid
TL;DR: This new method maintains the high sensitivity and low protein-to-protein variation associated with the Lowry technique and demonstrates a greater tolerance of the bicinchoninate reagent toward such commonly encountered interferences as nonionic detergents and simple buffer salts.
Book
Methods of Enzymatic Analysis
TL;DR: Methods of enzymatic analysis, Methods of enzymes analysis, the authors, Methods of enzyme analysis, enzymatics, methods of enzymes, and methods of analysis, method of enzymes.
Journal ArticleDOI
A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein samples
TL;DR: The original Lowry method of protein determination has been modified by the addition of sodium dodecyl sulfate in the alkali reagent and an increase in the amount of copper tartrate reagent to be used with membrane and lipoprotein preparations without prior solubilization or lipid extraction.