Testing for purity in proteins by gel electrophoresis

Peterson, Robert F.

doi:10.1021/jf60176a009

Cited by 14 publications

(2 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Urea and detergents can dissociate many different types of bonds as well as protein-lipid (or carbohydrate) interactions, whereas thiol reagents are more specific for (-SH) associated linkages (Anderson, 1968;Sondack and Light, 1971;Stankewicz, 1971;Wall, 1971). Since the purpose of this investigation was to confine the induced changes as much as possible to sulfur-containing linkages, total protein extracts from peanuts and fractions separated by DEAEcellulose chromatography were treated with d-ME or DTT only, and/or frozen storage, and then examined for molecular changes by gel electrophoretic techniques (Ornstein, 1964;Peterson, 1971).…”

Section: Resultsmentioning

confidence: 99%

Gel electrophoretic analysis of peanut proteins and enzymes. II. Effects of thiol reagents and frozen storage

Cherry¹,

Ory²

1973

J. Agric. Food Chem.

View full text Add to dashboard Cite

Peanut proteins and enzymes solubilized in the presence of high concentrations of dithiothreitol (DTT) or d-mercaptoethanol (d-ME), then examined by polyacrylamide or starch gel electrophoresis, showed significant changes in their mobilities and activities, respectively, when compared to those of control extracts (without thiol-reducing compounds). Frozen storage altered the solubility characteristics and electrophoretic patterns of these proteins, especially when the samples contained high concentrations of a reducing reagent. These changes were quite noticeable with protein fractions separated from arachin and with enzymes after DEAE-cellulose chromatography.The results indicate that thiol-reducing compounds and/or frozen storage promote many in vitro changes (e.g., molecular weight, conformational, structural, steric hindrance, and functional properties) in extracted peanut proteins and enzymes.Reactive thiol groups have several roles in proteins; e.g., they help to maintain protein conformation and stability

show abstract

Section: Resultsmentioning

confidence: 99%

Gel electrophoretic analysis of peanut proteins and enzymes. II. Effects of thiol reagents and frozen storage

Cherry¹,

Ory²

1973

J. Agric. Food Chem.

View full text Add to dashboard Cite

show abstract

“…The theoretical and methodological details for proteins including a preliminary work on a-lactalbumin are available. 209 The electro-focusing of milk proteins, a technique applied only recently, has been reported to resolve proteins differing in their isoelectric points only by 0.2 pH units. 1 S6 Of special interest are the recent reports on the constituent carbohydrates of bovine a-lactalbumin, suggesting that the type and quantity of carbohydrates associated with a bovine a-lactalbumin preparation depend to a large extent on the methods of isolation, fractionation, and purification.…”

Section: Heterogeneity Of Crystalline Preparationsmentioning

confidence: 99%

Chemistry and biological function of α‐lactalbumin

Shukla

Ebner

1973

C R C Critical Reviews in Food Technology

View full text Add to dashboard Cite

Preparation of rehydratable polyacrylamide gels and their application in ultrathin‐layer isoelectric focusing

et al. 1986

View full text Add to dashboard Cite

A new approach to isoelectric focusing in polyacrylamide gels is described, based on the use of rehydratable gels which in dry form could be stored for extended periods and which prior to use were rehydrated with solutions of any composition. Ultrathin 60-240 pm polyacrylamide gels, with different composition (5 % T, 3 % C; 3 % T, 4 % C ; 3 % T, 20 % C), were polymerized under well-standardized conditions and, after polymerization, washed exhaustively with distilled water to remove any unreacted monomers, catalysts or solublepolymers. The washed gels wereimpregnated with suitable additives, before drying, to preserve gel functionality on storage. Polyol compounds, such as glycerol, sorbitol and dextran, as well as synthetic polymers like polyethylene glycol and polyvinylpyrrolidone, were the most efticient additives when incorporated into the gel in a concentration of 1 -10 %, either as single substances or in different combinations. Prior to isoelectric focusing the dry gels were rehydrated to the original gel volume with a solution of carrier ampholytes, in some experiments with added separators or urea. Kinetic studies have shown rehydration, depending on gel thickness, to be complete within a few minutes. Isoelectric focusing in rehydratable gels was consistently more reproducible than in wet gels by such criteria as regularity of patterns and coalescence of marker proteins, including ferritin, applied at different positions. Rehydratable gels tolerated higher field strengths at the final stage of isoelectric focusing, with typical valuesof 500-900 V/cm and thus, at agiven volt x hour product, equilibrium focusing could be attained in a shorter time, with improved resolution and sharper zones. Ultrathin-layer isoelectric focusing in rehydratable gels proved insensitive to high salt concentrations (up to 0.5 M) of the samples. Rehydratable gels represent a new generation of gels, excelling over the traditional wet gels by better standardized properties, convenient handling and unsurpassed flexibility. tetramethylethylenediamine; DHEBA, NJ-( 1,2-dihydroxyIethylene)bisacrylamide; HEPES, N-(2 hydroxyethyl)piperazine-N'-2 ethanesulfonic acid; ACES, N-(2-acetamido)-2-aminoethanesulfonic acid; BICINE, N.N-bisl2-hydroxyethyl)glycine; Vh, volt X hour; IPG. immmobilized pH gradient 'D

show abstract

Testing for purity in proteins by gel electrophoresis

Cited by 14 publications

References 32 publications

Gel electrophoretic analysis of peanut proteins and enzymes. II. Effects of thiol reagents and frozen storage

Gel electrophoretic analysis of peanut proteins and enzymes. II. Effects of thiol reagents and frozen storage

Chemistry and biological function of α‐lactalbumin

Preparation of rehydratable polyacrylamide gels and their application in ultrathin‐layer isoelectric focusing

Contact Info

Product

Resources

About