scholarly journals Reduction of Sulphite to Sulphide Catalysed by Desulfoviridin From Desulfovibrio gigas

1974 ◽  
Vol 27 (1) ◽  
pp. 7 ◽  
Author(s):  
HE Jones ◽  
GW Skyring
Keyword(s):  
Column Chromatography ◽  
Gel Electrophoresis ◽  
Major Band ◽  
Minor Band ◽  
Desulfovibrio Gigas ◽  
A Minor

Desulfoviridin from D. gigas was partially purified by column chromatography and further purified by gel electrophoresis into a major band preparation and a minor band preparation. All partially purified and electrophoretically purified preparations catalysed the methylviologen-linked reduction of sulphite to sulphide, but stoichiometric reduction to sulphide was not demonstrated with the major band preparation. Desulfoviridin did not catalyse the reduction of thiosulphate or trithionate.

scholarly journals The dominant PNM2- mutation which eliminates the psi factor of Saccharomyces cerevisiae is the result of a missense mutation in the SUP35 gene.

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 659-670 ◽  
Author(s):  
S M Doel ◽  
S J McCready ◽  
C R Nierras ◽  
B S Cox
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Suppressor Gene ◽  
Chain Termination ◽  
Major Band ◽  
Minor Band ◽  
Terminal Domain ◽  
Translation Fidelity ◽  
Extrachromosomal Element ◽  
A Minor ◽  
Sup35 Gene

Abstract The PNM2- mutation of Saccharomyces cerevisiae eliminates the extrachromosomal element psi. PNM2 is closely linked to the omnipotent suppressor gene SUP35 (also previously identified as SUP2, SUF12, SAL3 and GST1). We cloned PNM2- and showed that PNM2 and SUP35 are the same gene. We sequenced the PNM2- mutant allele and found a single G-->A transition within the N-terminal domain of the protein. We tested the effects of various constructs of SUP35 and PNM2- on psi inheritance and on allosuppressor and antisuppressor functions of the gene. We found that the C-terminal domain of SUP35 protein (SUP35p) could be independently expressed; expression produced dominant antisuppression. Disruption of the N-terminal domain of PNM2- destroyed the ability to eliminate psi. These results imply that the domains of SUP35p act in an antagonistic manner: the N-terminal domain decreases chain-termination fidelity, while the C-terminal domain imposes fidelity. Two transcripts were observed for SUP35, a major band at 2.4 kb and a minor band at 1.3 kb; the minor band corresponds to 3' sequences only. We propose a model for the function of SUP35, in which comparative levels of N- and C-terminal domains of SUP35p at the ribosome modulate translation fidelity.

Two-dimensional gel electrophoresis can be used to examine chromatographic effluent fractions from displacement column chromatography.

1982 ◽  
Vol 28 (4) ◽  
pp. 998-999 ◽  
Author(s):  
A R Torres ◽  
G G Krueger ◽  
E A Peterson
Keyword(s):  
Human Serum ◽  
Column Chromatography ◽  
Gel Electrophoresis ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Gel Method ◽  
Minor Protein ◽  
Protein Components ◽  
A Minor

Abstract We show how two-dimensional gel electrophoresis can be used to monitor protein components in effluent fractions from a displacement column. A minor protein in human serum, of interest in studies on psoriasis and highly enriched by using carboxymethyldextrans as displacers on DEAE-Sephacel, was easily detected in the effluent fractions with the two-dimensional gel method because its concentration was sufficiently high and there was no interference by the carboxymethyldextrans or salt.

scholarly journals Interaction of aldolase with actin-containing filaments. Structural studies

1980 ◽  
Vol 186 (1) ◽  
pp. 99-104 ◽  
Author(s):  
M Stewart ◽  
D J Morton ◽  
F M Clarke
Keyword(s):  
Structural Changes ◽  
Preceding Paper ◽  
Ultrastructural Changes ◽  
Cross Linking ◽  
Fructose Bisphosphate ◽  
Major Band ◽  
Minor Band ◽  
Computer Methods ◽  
Fructose Bisphosphate Aldolase ◽  
A Minor

Electron micrographs of the paracrystals formed when fructose bisphosphate aldolase (EC 4.1.2.13) is added to actin-containing filaments were analysed by computer methods so that ultrastructural changes could be correlated with the various stoicheiometries of binding determined in the preceding paper [Walsh, Winzor, Clarke, Masters & Morton (1980) Biochem. J. 186, 89-98]. Paracrystals formed with aldolase and either F-actin or F-actin-tropomyosin have a single light transverse band every 38 nm, which is due to aldolase molecules cross-linking the filaments. In contrast, the paracrystals formed between aldolase and F-actin-tropomyosin-troponin filaments show two transverse bands every 38 nm: a major band, interpreted as aldolase binding to troponin, and a minor band, interpreted as aldolase cross-linking the filaments. The intensity of the minor band varies with Ca2+ concentration, being greatest when the Ca2+ concentration is low. A model for the different paracrystal structures which relates the various patterns and binding stoicheiometries to structural changes in the actin-containing filaments is proposed.

Erythrina Cristagalli Lectin-reactive α-fetoprotein-E2: A Marker of Hepatocellular Carcinoma and Other Malignancies

1998 ◽  
Vol 13 (1) ◽  
pp. 24-29 ◽  
Author(s):  
M. Kamei ◽  
A. Misawa ◽  
J. Arai ◽  
K. Kamakura ◽  
K. Taketa
Keyword(s):  
Hepatocellular Carcinoma ◽  
Chronic Hepatitis ◽  
Yolk Sac ◽  
Antibody Affinity ◽  
Major Band ◽  
Minor Band ◽  
Affinity Electrophoresis ◽  
Hepatocellular Carcinomas ◽  
Yolk Sac Tumors ◽  
A Minor

A newly isolated lectin Erythrina cristagalli (ECL) was tested for separation of human α-fetoprotein (AFP) glycoforms by affinity electrophoresis at 0.5 mg/ml and separated AFP bands were detected by antibody-affinity blotting. Three AFP bands, AFP-E1, AFP-E2 and AFP-E3 in order of increasing affinity, were obtained. Sera from control patients with chronic hepatitis and cirrhosis gave a major band of AFP-E1 and a minor or trace band of AFP-E2 (3.4±2.3%), while those from patients with mostly advanced hepatocellular carcinomas had increased proportions of AFP-E2 band (16.6±10.2%). With a cutoff level of 8% (mean+2SD of AFP-E2 for controls), the sensitivity for hepatocellular carcinoma was 72% at a specificity of 100%. Gastrointestinal tumors had much higher percentages of AFP-E2 and occasionally positive AFP-E3. Most of the yolk sac tumors examined showed AFP-E3 in addition to AFP-E2, although AFP-E3 was a minor band. Thus, AFP-E2 is potentially a clinically useful marker for differentiation of increased AFP in hepatocellular carcinoma and other malignancies from that in precancerous chronic hepatitis or cirrhosis.

scholarly journals The α-amylase of the beetle Callosobruchus chinensis. Purification and action pattern

1971 ◽  
Vol 121 (2) ◽  
pp. 317-320 ◽  
Author(s):  
H. Podoler ◽  
S. W. Applebaum
Keyword(s):  
Column Chromatography ◽  
Gel Electrophoresis ◽  
Callosobruchus Chinensis ◽  
Action Pattern ◽  
Iodine Complex ◽  
Co Precipitation

Callosobruchus chinensis larval amylase was isolated and purified in five steps, which included co-precipitation with glycogen and column chromatography on ECTEOLA-cellulose. The enzyme was homogeneous by disc gel electrophoresis on polyacrylamide. The α-amylase nature was evidenced by the action on amylopectin β-amylase limit-dextrin, by the effect on the substrate–iodine complex and by the action pattern on several polysaccharide substrates. These action patterns are compared with those of other α-amylases.

Novel Catalatic Proteins of Bakers' Yeast. I. An Atypical Catalase

1973 ◽  
Vol 51 (11) ◽  
pp. 1551-1555 ◽  
Author(s):  
Tony C. M. Seah ◽  
A. R. Bhatti ◽  
J. G. Kaplan
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Native Protein ◽  
Wild Type ◽  
Major Band ◽  
Subunit Molecular Weight ◽  
Purification And Properties

At any stage of growth of a wild-type bakers' yeast, some 20% of the catalatic activity of crude extracts is not precipitable by means of antibody prepared against the typical catalase (catalase T), whose purification and properties have been previously described. Some of this catalatic activity is due to the presence of an atypical catalase (catalase A), a heme protein, with a molecular weight estimated as 170 000 – 190 000, considerably lower than that of the usual catalases (225 000 – 250 000). Preparations of catalase A were found to be homogeneous in the analytical ultracentrifuge and in polyacrylamide gel electrophoresis. Its subunit molecular weight, determined from its iron content, was 46 500, virtually the same as that of the major band obtained in gel electrophoresis in the presence of sodium dodecyl sulfate, suggesting that the native protein is tetrameric. Its specific activity is in the range of those reported for other typical catalases.

scholarly journals Identification of Gz alpha as a pertussis toxin-insensitive G protein in human platelets and megakaryocytes

Blood ◽  
1991 ◽  
Vol 78 (5) ◽  
pp. 1247-1253 ◽  
Author(s):  
AW Gagnon ◽  
DR Manning ◽  
L Catani ◽  
A Gewirtz ◽  
M Poncz ◽  
...  
Keyword(s):  
G Protein ◽  
Cell Lines ◽  
Complete Sequence ◽  
Human Platelets ◽  
Northern Blotting ◽  
Nucleotide Sequencing ◽  
Major Band ◽  
Surface Receptors ◽  
G Protein Alpha Subunit ◽  
A Minor

Abstract G proteins mediate the interaction between cell surface receptors and intracellular effectors. Recent studies have shown that human retina and rat brain contain mRNA encoding a novel 40-Kd G protein alpha subunit referred to as Gz alpha. Studies with an antiserum selective for the predicted sequence of this protein have suggested that a similar protein is present in human platelets and is phosphorylated during platelet activation. To better understand the structure and function of this protein, the present studies examine its sequence in platelets and compare its abundance in human platelets, megakaryocytes, and two megakaryoblastic cell lines, HEL cells and Dami cells. Three different Gz alpha-selective antisera reacted with a 40-Kd protein in platelet membranes. None of these detected a corresponding protein in HEL or Dami cells, despite the presence in both cell lines of proteins recognized by antisera selective for three members of the Gi alpha family. Northern blotting with a Gz alpha-specific probe prepared from retinal Gz alpha showed two hybridizing species in platelet RNA: a major band at 3.5 kb and a minor band at 2.2 kb. Both were detectable in HEL and Dami cells, but at greatly reduced levels compared with platelets. RNA encoding Gz alpha was also detected in individual human megakaryocytes by in situ hybridization. The amount present approached that of Gi alpha 2′ the most abundant of the Gi alpha species present in platelets. The complete sequence of the platelet homolog to Gz alpha was determined from platelet RNA amplified by the polymerase chain reaction. The encoded protein was the same as those obtained in brain and retina. Thus, based on immunoreactivity and nucleotide sequencing, platelets and megakaryocytes contain substantial quantities of a protein identical to brain and retinal Gz alpha. The paucity of Gz alpha protein and RNA in the megakaryoblastic cell lines suggests that either there has been a selective loss of the ability to synthesize Gz alpha from these cells or that Gz alpha appears at a later stage in megakaryocyte development than does Gi alpha.

The soluble adenosine triphosphatase of Thiobacillus ferrooxidans

1975 ◽  
Vol 21 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Catherine Adapoe ◽  
Marvin Silver
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Gel Electrophoresis ◽  
Inorganic Phosphate ◽  
Adenosine Triphosphatase ◽  
Thiobacillus Ferrooxidans ◽  
Polyacrylamide Gel Electrophoresis ◽  
Histochemical Analysis ◽  
Ph Optimum ◽  
Major Band

Adenosine triphosphatase (ATPase) from Thiobacilhis ferrooxidans was purified 55-fold. Polyacrylamide gel electrophoresis of the most purified fraction showed only one major band; histochemical analysis showed that the ATPase activity was associated with this band. The pH optimum is 9–10. The enzyme hydrolyzed ATP stoichiometrically to ADP and inorganic phosphate, the Km for this substrate being 7.75 × 10−3 M. GTP and ITP are alternate substrates, the Km values for these being 6.71 × 10−3 M and 3.12 × 10−3 M, respectively. ADP is slightly hydrolyzed. Magnesium, manganese, and calcium can serve as cofactors; Km values for these are 2.0 × 10−3 M, 9.4 × 10−4 M, and 8.0 × 10−4 M, respectively. The enzyme activity was not activated by either sodium or potassium, but a combination of the two ions were inhibitory. Azide and p-hydroxymercuribenzoate strongly inhibited the enzyme activity, whereas cyanide, dinitrophenol, and N, N′-dicyclohexylcarbodiimide (DCCD) were without effect. The enzyme was cold labile at 0 °C, but was more stable at 18–24 °C.

STUDIES ON PLASMINOGEN: IV. ALTERATION OF BOVINE AND HUMAN PLASMINOGENS DURING ISOLATION

1966 ◽  
Vol 44 (4) ◽  
pp. 469-473 ◽  
Author(s):  
John Y. S. Chan ◽  
Edwin T. Mertz
Keyword(s):  
Ionic Strength ◽  
Gel Electrophoresis ◽  
Deae Cellulose ◽  
Starch Gel Electrophoresis ◽  
Major Band ◽  
Starch Gel ◽  
Human Plasminogen

Bovine and human plasminogen preparations were analyzed by starch-gel electrophoresis at pH 2.5 and 0.10 ionic strength. The bands were activated with urokinase and the proteolytic and esterolytic activities measured. Bovine euglobulin contains one plasminogen band, B-1. Plasminogen prepared from bovine euglobulin by continuous electrophoresis at pH 3.5 contains B-1 and a faster plasminogen band, B-2. B-1 and B-2 are also found in bovine plasminogen prepared by DEAE-cellulose chromatography. All three preparations on activation give the same two plasmin bands on starch gel. Human euglobulin also contains two active plasminogen bands H-1 and H-2. Plasminogen prepared from human euglobulin by continuous electrophoresis at pH 3.5 contains H-1, H-2, and a faster minor plasminogen band, H-3. All highly purified human plasminogens derived from Cohn fraction III contain either H-3 as a major band and an additional plasminogen band, H-4, or only H-3, but no H-1 and H-2. On activation with urokinase or streptokinase, human plasminogen preparations give one or two plasmin bands. It is concluded that bovine B-2 and human H-3 and H-4 are altered forms of euglobulin plasminogen created during isolation procedures. Essentially pure human H-3 can be prepared by continuous electrophoresis from Cutter plasminogen.

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