scholarly journals Dodecyl sulphate/polyacrylamide-gel electrophoresis at low pH values and low temperatures

1979 ◽  
Vol 181 (3) ◽  
pp. 759-761 ◽  
Author(s):  
R Lichtner ◽  
H U Wolf
Keyword(s):  
Low Temperatures ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Catalyst System ◽  
Low Ph ◽  
Polyacrylamide Gel ◽  
Buffer System ◽  
Simple Method ◽  
Ph Values

A simple method is described for dodecyl sulphate/polyacrylamide-gel electrophoresis of pH- and temperature-labile biological intermediates. The method is based on a catalyst system that works at temperatures of 2–4 degrees C and pH values of 2–4 and an appropriate buffer system containing Li+ or Tris [CH2OH–C(CH2OH)2–NH3+] instead of Na+. This system does not lead to the precipitation of 1% dodecyl sulphate.

A novel Bicine running buffer system for doubled sodium dodecyl sulfate – polyacrylamide gel electrophoresis of membrane proteins

2006 ◽  
Vol 27 (14) ◽  
pp. 2984-2995 ◽  
Author(s):  
Taufika Islam Williams ◽  
Jennifer C. Combs ◽  
Anup P. Thakur ◽  
Herbert J. Strobel ◽  
Bert C. Lynn
Keyword(s):  
Membrane Proteins ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Buffer System ◽  
Dodecyl Sulfate

scholarly journals Purification of 2-oxoaldehyde dehydrogenase and its dependence on unusual amines

1975 ◽  
Vol 149 (3) ◽  
pp. 609-617 ◽  
Author(s):  
J Dunkerton ◽  
S P James
Keyword(s):  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
General Structure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Maximum Activity ◽  
Polyacrylamide Gel ◽  
Ph Optimum ◽  
Ph Values ◽  
Sheep Liver ◽  
Living Tissues

1. 2-Oxoaldehyde dehydrogenase was purified from sheep liver and gave one band on polyacrylamide-gel electrophoresis. 2. The enzyme was completely dependent for its activity on the presence of Tris or one of a number of related amines, all of general structure: (See article). When more than one R group was hydrogen no enzyme activity was observed. 3. Only one of these amines is known to exist in living tissues and large concentrations of all amines were required for maximum activity. L-2-Aminopropan-1-ol was the most effective amine on the basis of substrate Km and Vmax. values and the amine Km values. 4. The enzyme was activated by phosphate which lowered the Km values for methylglyoxal, amine and NAD+. 5. The pH optimum of the enzyme was 9.3 and there was no activity at pH values below 7.8. A search for activators that might produce activity at pH 7.4 proved unsuccessful. 6. The enzyme was inhibited by rather large concentrations of barbiturates (6-46 mM) and nitro-alcohol analogues of the activating amines (66-139 mM).

scholarly journals Purification and properties of adenylyl sulphate:ammonia adenylyltransferase from Chlorella catalysing the formation of adenosine 5′-phosphoramidate from adenosine 5′-phosphosulphate and ammonia

1981 ◽  
Vol 195 (3) ◽  
pp. 545-560 ◽  
Author(s):  
Heinz Fankhauser ◽  
Jerome A. Schiff ◽  
Leonard J. Garber
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Low Ph ◽  
Polyacrylamide Gel ◽  
Ph Optimum ◽  
Unknown Compound ◽  
Reactive Blue 2

Extracts of Chlorella pyrenoidosa, Euglena gracilis var. bacillaris, spinach, barley, Dictyostelium discoideum and Escherichia coli form an unknown compound enzymically from adenosine 5′-phosphosulphate in the presence of ammonia. This unknown compound shares the following properties with adenosine 5′-phosphoramidate: molar proportions of constituent parts (1 adenine:1 ribose:1 phosphate:1 ammonia released at low pH), co-electrophoresis in all buffers tested including borate, formation of AMP at low pH through release of ammonia, mass and i.r. spectra and conversion into 5′-AMP by phosphodiesterase. This unknown compound therefore appears to be identical with adenosine 5′-phosphoramidate. The enzyme that catalyses the formation of adenosine 5′-phosphoramidate from ammonia and adenosine 5′-phosphosulphate was purified 1800-fold (to homogeneity) from Chlorella by using (NH4)2SO4 precipitation and DEAE-cellulose, Sephadex and Reactive Blue 2–agarose chromatography. The purified enzyme shows one band of protein, coincident with activity, at a position corresponding to 60000–65000 molecular weight, on polyacrylamide-gel electrophoresis, and yields three subunits on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of 26000, 21000 and 17000 molecular weight, consistent with a molecular weight of 64000 for the native enzyme. Isoelectrofocusing yields one band of pI4.2. The pH optimum of the enzyme-catalysed reaction is 8.8. ATP, ADP or adenosine 3′-phosphate 5′-phosphosulphate will not replace adenosine 5′-phosphosulphate, and the apparent Km for the last-mentioned compound is 0.82mm. The apparent Km for ammonia (assuming NH3 to be the active species) is about 10mm. A large variety of primary, secondary and tertiary amines or amides will not replace ammonia. One mol.prop. of adenosine 5′-phosphosulphate reacts with 1 mol.prop. of ammonia to yield 1 mol.prop. each of adenosine 5′-phosphoramidate and sulphate; no AMP is found. The highly purified enzyme does not catalyse any of the known reactions of adenosine 5′-phosphosulphate, including those catalysed by ATP sulphurylase, adenosine 5′-phosphosulphate kinase, adenosine 5′-phosphosulphate sulphotransferase or ADP sulphurylase. Adenosine 5′-phosphoramidate is found in old samples of the ammonium salt of adenosine 5′-phosphosulphate and can be formed non-enzymically if adenosine 5′-phosphosulphate and ammonia are boiled. In the non-enzymic reaction both adenosine 5′-phosphoramidate and AMP are formed. Thus the enzyme forms adenosine 5′-phosphoramidate by selectively speeding up an already favoured reaction.

Analysis of extracellular proteins by native polyacrylamide gel electrophoresis with infiltrated leaf tissue: application to pathogenesis-related proteins

1988 ◽  
Vol 66 (6) ◽  
pp. 1227-1229 ◽  
Author(s):  
Jean Grenier ◽  
François Côté ◽  
Alain Asselin
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Leaf Tissue ◽  
Polyacrylamide Gel ◽  
Simple Method ◽  
Pathogenesis Related Proteins ◽  
Intercellular Fluid ◽  
Pathogenesis Related ◽  
Native Polyacrylamide Gel Electrophoresis ◽  
Related Proteins

In addition to polyacrylamide gel electrophoretic analysis of intercellular fluid extracts, a simple method of detection of extracellular pathogenesis-related proteins was based on direct native polyacrylamide gel electrophoresis for acidic and basic proteins with leaf tissue infiltrated with 150 mM sucrose. This technique allowed for the detection of the complete set of tobacco pathogenesis-related proteins without having to extract the intercellular fluid by low-speed centrifugation. A major advantage of the technique is the capacity to observe the distribution of extracellular endogenous or exogenous proteins in the tissue directly subjected to electrophoresis.

scholarly journals Purification of rat intestinal maltase/glucoamylase and its anomalous dissociation either by heat or by low pH

1978 ◽  
Vol 173 (2) ◽  
pp. 553-563 ◽  
Author(s):  
P R Flanagan ◽  
G G Forstner
Keyword(s):  
New Species ◽  
Sialic Acid ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Low Ph ◽  
Precipitin Line ◽  
Molecular Weights ◽  
Ph Values

Maltase-glucoamylase, a microvillous membrane ectoenzyme, was solubilized from rat intestinal mucosa by digestion with papain and subsequently purified to homogeneity with an overall yield of 10–20%. An antibody to the purified enzyme formed a single precipitin line in immunodiffusion experiments with an intestinal homogenate. The enzyme was shown to be an acidic glycoprotein (20% sugar by weight) which contained low amounts of cysteine and no sialic acid. At pH3–6, maltase activity was slowly lost, but the enzyme was re-activated by re-adjustment of the pH to neutrality. However, in the presence of sodium dodecyl sulphate, acid pH values inactivated maltase irreversibly, and at the same time converted the enzyme (mol.wt. 500000 approx.) into five new species with apparent molecular weights ranging from 134000 to 480000 as judged by polyacrylamide-gel electrophoresis. The same five fragments were also formed by boiling the enzyme for brief periods in the presence of sodium dodecyl sulphate or urea either with or without reducing agents. The dissociated species were stable on re-electrophoresis, and amino acid analysis showed them to be very similar to each other and to the original enzyme. The bands migrated anomalously on polyacrylamide gels of different concentration, thereby preventing the assignment of precise molecular weights. It is possible that the five species may represent stable aggregates of a common monomer of the enzyme.

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