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
Probing the conformation and orientation of adsorbed enzymes using side-chain modification.
TL;DR: Methods using side-chain-specific chemical modification of solvent-exposed tryptophan residues to complement CD spectroscopy and bioactivity assays to provide greater detail regarding whether changes in enzyme bioactivity following adsorption are due to adsorbed orientation and/or adsor adaptation-induced changes in the overall structure are provided.
Journal ArticleDOI
Conversion of methionine to methional by Lactococcus lactis.
TL;DR: This work describes for the first time that L. lactis can convert enzymatically methionine to methional in a process mediated by aminotransferase and alpha-ketoacid decarboxylase activities, and seems to be strain dependent.
Journal ArticleDOI
Serum and bronchial lavage fluid concentrations of IL-8, SLPI, sCD14 and sICAM-1 in patients with COPD and asthma
Camilla Hollander,Brigita Sitkauskiene,Raimundas Sakalauskas,Ulla Westin,Sabina Janciauskiene +4 more
TL;DR: The findings point to the importance of selecting a correct biological fluid when analyzing specific biomarkers, and also show that of 4 measured biomarker, only the BAL IL-8 was higher in COPD patients when compared to asthma.
Journal ArticleDOI
Synthesis and pharmacological evaluation of like- and unlike-configured tetrahydro-2-benzazepines with the α-substituted benzyl moiety in the 5-position
Peer Hasebein,Bastian Frehland,Kirstin Lehmkuhl,Roland Fröhlich,Dirk Schepmann,Bernhard Wünsch +5 more
TL;DR: Analysis of the relationship between the structure and the σ1 affinity revealed that large substituents such as the butyl, benzyl or 4-phenylbutyl moiety at the benzazepine N-atom resulted in high affinity ligands.
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Purification and Properties of a Highly Thermostable, Sodium Dodecyl Sulfate-Resistant and Stereospecific Proteinase from the Extremely Thermophilic Archaeon Thermococcus stetteri.
TL;DR: The cultivation of the extremely thermophilic archaeon Thermococcus stetteri in a dialysis membrane reactor was paralleled by the production of an extremely heat-stable proteinase(s), showing thermostability, SDS resistance, relatively narrow substrate specificity, high stereospecificity, and limited catalytic efficiency.
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.