Varying electrophoretic mobility of an esterase caused by a factor in extracts of Bacillus stearothermophilus cells

1982 ◽  
Vol 28 (12) ◽  
pp. 1355-1364 ◽  
Author(s):  
Eiji Majima ◽  
Mikiko Abe ◽  
Shiro Higashi

The esterase pattern on polyacrylamide gel of extracts from Bacillus stearothermophilus grown at different temperatures from 45 to 71 °C was examined by slab gel electrophoresis. The esterase pattern showed the presence of eight esterase bands in the extracts from bacterial cells grown at 60 °C. These bands could be divided into two groups. One group included seven esterase bands which showed constant electrophoretic mobilities at different growth temperatures. The other group included one esterase band, Est-b, which showed different mobilities depending on growth temperature. A factor, which increased the mobility of Est-b, could be separated from cell extracts by gel filtration. The mobility of partially purified Est-b was regulated by addition of various amounts of the factor. At 70 °C, the thermostability of partially purified Est-b was increased by adding the factor; this was accompanied by competitive inhibition of the enzyme activity.


1976 ◽  
Vol 159 (3) ◽  
pp. 579-583 ◽  
Author(s):  
R Porta ◽  
C Esposito ◽  
A Martin ◽  
G D Pietra

Arginase was purified about 1800-fold from extracts of human full-term placenta; the enzyme appeared to be homogenous by disc electrophoresis and molecular-sieve chromatography. The mol. wt. determination by gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis yielded a value of 70000 for the most pure and the partially purified enzyme. The human placenta arginase is a metalloenzyme with an optimum pH of 9.1. The Km for L-arginine is 27 mM. L-Ornithine and L-lysine show competitive inhibition with Ki values of 6.3 and 14 mM respectively.



1974 ◽  
Vol 139 (2) ◽  
pp. 391-398 ◽  
Author(s):  
Susan Wilkinson ◽  
Jeremy R. Knowles

The purification of valyl-tRNA synthetase from Bacillus stearothermophilus is described. The protein was greater than 90% homogeneous on polyacrylamide-gel electrophoresis after more than 850-fold purification. It has a molecular weight of 110000, and no evidence was found for the presence of subunit structure. The properties of the purified enzyme were compared with those of purified valyl-tRNA synthetase from Escherichia coli. The thermal stability, pH-stability and dependence of activity on the temperature and pH of the assay are reported. The two enzymes recognize and charge tRNAVal from crude tRNA of the mesophile E. coli and of the thermophile B. stearothermophilus, indiscriminately. The gel-filtration method was extended to measure the binding of tRNA to synthetase directly. Binding constants for tRNAVal to valyl-tRNA synthetase from B. stearothermophilus were determined between 5° and 60°C.



1980 ◽  
Vol 189 (3) ◽  
pp. 491-499 ◽  
Author(s):  
Richard A. Berg ◽  
Winston W.-Y. Kao ◽  
Nancy L. Kedersha

Embryonic-chick tendon cells were incubated in suspension for 4h with 14C-labelled amino acids, cell extracts were subjected to gel filtration, and the effluent was examined by rocket immunoelectrophoresis by using antibodies specific for the β-subunit of chick prolyl hydroxylase. Two peaks of immunoreactive protein were found. The first peak contained 40% of the immunoreactive protein eluted from the column and 100% of the enzyme activity. Polyacrylamide-slab-gel electrophoresis in sodium dodecyl sulphate of an immunoprecipitate of this peak demonstrated that it consisted of the tetrameric form of prolyl hydroxylase, subunit composition α2β2 where α and β are non-identical subunits. Only the α-subunits were labelled, indicating that they were synthesized during the 4h labelling period. The β-subunits were unlabelled, indicating that they had been synthesized before the labelling period. The second peak eluted from the gel-filtration column contained 60% of the immunoreactive protein eluted from the column and was enzymically inactive. Polyacrylamide-slab-gel electrophoresis of an immunoprecipitate of this peak indicated that it consisted of a single labelled polypeptide chain, identified as cross-reacting protein, which was related to, but not identical with, the β-subunit of prolyl hydroxylase. Pulse–chase experiments were performed on cultured chick tendon cells to demonstrate that α-subunits and cross-reacting protein had half-lives of about 60h. The half-life of β-subunits was considerably longer, and the kinetic pattern was consistent with their being derived from a labelled precursor such as cross-reacting protein. The data presented here indicate that the active tetrameric form of prolyl hydroxylase in cells is assembled from α-subunits which are newly synthesized, and from β-subunits which are derived from cross-reacting protein.



1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.



1972 ◽  
Vol 27 (03) ◽  
pp. 610-618 ◽  
Author(s):  
H Graeff ◽  
R von Hugo

SummaryThe observation of fibrinogen derivatives with a molecular weight higher than the parent molecule in human cases of DIC initiated the present methodological study. These derivatives were identified by the following methods : 2.5 M β-alanine precipitation of the plasma samples, PAA gel electrophoresis, intra gel immunoprecipitation and agarose gel chromatography. In the plasma of a patient with severe eclampsia and laboratory signs of DIC two derivatives with a molecular weight higher than that of fibrinogen were identified according to their relative electrophoretic mobilities: 0.18 and 0.28 × 10−5 cm2/V × sec (fibrinogen: 0.43 × 10−5 cm2/V × sec). Electrophoretic studies in the presence of 5 M urea indicated that the 0.28 derivative is a complex probably formed by fibrinogen and a fibrin monomer.



1981 ◽  
Vol 59 (5) ◽  
pp. 771-775 ◽  
Author(s):  
Moira M. Ferguson ◽  
David L. G. Noakes ◽  
Roy G. Danzmann

Examination of 17 presumptive gene loci by starch-gel electrophoresis revealed differential mobilities only at acid phosphatase-1, alcohol dehydrogenase, esterase-1, and phosphoglucomutase between Nocomis biguttatus and N. micropogon. No intraspecific variation was observed for any loci. The genetic identity (I) and genetic distance (D) were 0.874 and 0.134, respectively. The correlation of electrophoretic mobilities and nuptial tubercle pattern in sexually dimorphic males supports the present taxonomic distinction of these species and provides a simple, unambiguous means of identifying any individuals.Stepwise discriminant function analysis of a series of mensural characters was used to compare fish identified as to species by electrophoresis. At best this correctly assigned fish to their respective species in 85.7% of cases, with a probability of misclassification of 0.1335.This study suggests these two are sibling species, based on a comparison of biochemical and morphological differentiation.



1991 ◽  
Vol 278 (1) ◽  
pp. 171-177 ◽  
Author(s):  
A J Rivett ◽  
S T Sweeney

The multicatalytic proteinase (MCP) is a high-molecular-mass non-lysosomal proteinase that gives rise to a characteristic pattern of bands of molecular mass 22-34 kDa on SDS/PAGE gels. Isoelectric-focusing gels of the enzyme purified from rat liver show 16 bands with isoelectric points in the range of pH 5-8.5. Two-dimensional PAGE gels reveal that there are more than the previously reported 13 polypeptides associated with the MCP from rat liver and show a pattern of 15-20 major spots and several minor ones, similar to that of MCP isolated from some other sources. Possible relationships between the different polypeptides were investigated by immunoblot analysis of electrophoretically purified proteinase subunits with affinity-purified subunit-specific antibodies as well as antibodies raised against individual denatured subunits of the complex. The results demonstrate that many of the major polypeptide components of the MCP complex are antigenically distinct. Moreover comparison of immunoreactive material in crude cell extracts with that in purified MCP preparations has shown that the polypeptides are not derived from a smaller number of higher-molecular-mass subunits. Also, individual subunits have the same apparent molecular mass in a variety of rat tissues, suggesting close similarity between MCPs of different tissues. The highest concentrations of MCP subunits occur in liver and kidney. Gel-filtration analysis of crude extracts has demonstrated that MCP polypeptides are also associated with a higher-molecular-mass complex, which may be the 26 S proteinase that has been implicated in the degradation of ubiquitin-protein conjugates.



1990 ◽  
Vol 10 (2) ◽  
pp. 131-139
Author(s):  
Oyewole Adeyemo ◽  
E. O. Okegbile ◽  
O. O. Olorunsogo

For the development of immunological contraception, attention is being concentrated on the possibility of using a sperm membrane antigen. Boar sperm membrane was extracted with triton-X 100 and fractionated by Sephadex G-150 column chromatography. The glycosylated and nonglycosylated portions of protein peaks from the gel filtration were obtained by fractionating on concanavalin A-Sepharose and eluting the bound protein with 0.3 M methyl mannoside. A glycosylated fraction was found to induce sperm agglutinating antibodies in rabbit. The partially purified protein has a molecular weight of 30 kilodaltons, as determined by sodium dodecyl polyaccyrlamide gel electrophoresis. Further work is planned on the histochemical determination of the origin of this protein and species cross-activity of the antibody.



2012 ◽  
Vol 27 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Juliusz Bianga ◽  
Guillaume Ballihaut ◽  
Christophe Pécheyran ◽  
Zahia Touat ◽  
Hugues Preud'homme ◽  
...  


1988 ◽  
Vol 254 (2) ◽  
pp. 419-426 ◽  
Author(s):  
P M Wiest ◽  
E J Tisdale ◽  
W L Roberts ◽  
T L Rosenberry ◽  
A A F Mahmoud ◽  
...  

Biosynthetic labelling experiments with cercariae and schistosomula of the multicellular parasitic trematode Schistosoma mansoni were performed to determine whether [3H]palmitate or [3H]ethanolamine was incorporated into proteins. Parasites incorporated [3H]palmitate into numerous proteins, as judged by SDS/polyacrylamide-gel electrophoresis and fluorography. The radiolabel was resistant to extraction with chloroform, but sensitive to alkaline hydrolysis, indicating the presence of an ester bond. Further investigation of the major 22 kDa [3H]palmitate-labelled species showed that the label could be recovered in a Pronase fragment which bound detergent and had an apparent molecular mass of 1200 Da as determined by gel filtration on Sephadex LH-20. Schistosomula incubated with [3H]ethanolamine for up to 24 h incorporated this precursor into several proteins; labelled Pronase fragments recovered from the three most intensely labelled proteins were hydrophilic and had a molecular mass of approx. 200 Da. Furthermore, reductive methylation of such fragments showed that the [3H]ethanolamine bears a free amino group, indicating the lack of an amide linkage. We also evaluated the effect of phosphatidylinositol-specific phospholipase C from Staphylococcus aureus: [3H]palmitate-labelled proteins of schistosomula and surface-iodinated proteins were resistant to hydrolysis with this enzyme. In conclusion, [3H]palmitate and [3H]ethanolamine are incorporated into distinct proteins of cercariae and schistosomula which do not bear glycophospholipid anchors. The [3H]ethanolamine-labelled proteins represent a novel variety of protein modification.



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