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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Cysteine and Disulfide Scanning Reveals a Regulatory α-Helix in the Cytoplasmic Domain of the Aspartate Receptor
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High-level expression in Saccharomyces cerevisiae enables isolation and spectroscopic characterization of functional human adenosine A2a receptor
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Construction and characterization of two recombinant bacteria that grow on ortho- and para-substituted chlorobiphenyls
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Journal ArticleDOI
Crystal structure of mannanase 26A from Pseudomonas cellulosa and analysis of residues involved in substrate binding.
Deborah Hogg,Eui-Jeon Woo,David N. Bolam,Vincent A. McKie,H.J. Gilbert,Richard W. Pickersgill +5 more
TL;DR: Functional analyses of mannanase 26A, informed by the crystal structure of the enzyme, provided important insights into the role of residues close to the catalytic glutamates, showing that Trp-360 played a critical role in binding substrate at the −1 subsite, whereas Tyr-285 was important to the function of the nucleophile catalyst.
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.