Membranes of chromaffin granules. Isolation and partial characterization of two proteins

1971 ◽  
Vol 122 (3) ◽  
pp. 298.1-304 ◽  
Author(s):  
Heide Hörtnagl ◽  
H. Winkler ◽  
J. A. L. Schöpf ◽  
W. Hohenwallner

Membranes of chromaffin granules were isolated from the adrenal glands of four different species. The solubilized membrane proteins could be resolved into several bands by polyacrylamide-gel electrophoresis (alkaline and acid gel systems). Two major protein components appeared to be common to the chromaffin granule membranes of ox, horse, pig and man. The various membrane proteins of bovine chromaffin granules were separated by filtration on Sephadex G-200 in the presence of sodium dodecyl sulphate. Two major membrane proteins (A and B) were obtained in purified form. Treatment of protein A with 2-mercaptoethanol before electrophoresis resulted in two more rapidly migrating subunits, whereas protein B was unaffected by mercaptoethanol treatment. The amino acid compositions of the two purified proteins were determined. They are very similar to that of the total membrane proteins but significantly different from that of the chromogranins, the soluble proteins of chromaffin granules.

1982 ◽  
Vol 60 (3) ◽  
pp. 356-363 ◽  
Author(s):  
M. S. Zhao ◽  
C. C. Liew

Antibodies were produced to phosphoprotein fraction, and a phosphoprotein B2 obtained by carboxyl methyl cellulose column chromatography and sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis as described previously (Biochem. J. 183, 147 (1979)). Production of the specific antibody was confirmed by double immunodiffusion. The phosphoprotein B2 (relative mass 68 000), which was isolated from the phosphoprotein fraction by SDS–polyacrylamide gel electrophoresis, specifically reacted with the antisera, as identified by "rocket" immunoelectrophoresis. Further characterization of the antibody to the phosphoprotein was carried out by isoelectrofocusing gel electrophoresis. The phosphoprotein, previously identified in the isoelectric point (pI) region 6.2–8.5, was subsequently reacted with antisera and 125I-labelled protein A. A prominent radioactive peak was identified in the region in which the phosphoprotein was focused. The radioimmunoactivity was proportional to the amount of phosphoproteins present in the isoelectric focusing gel. The presence of phosphoprotein in two types of mononucleosomes (MN1 and MN2) was demonstrated immunologically by use of the phosphoprotein antibody. The relationship between the phosphoprotein and chromatin structure, and possible role in gene regulation is discussed.


1976 ◽  
Vol 154 (1) ◽  
pp. 57-64 ◽  
Author(s):  
R A Mathews ◽  
T C Johnson ◽  
J E Hudson

A kinetic analysis of the appearance of 14C-labelled proteins in the surface membranes isolated from exponentially growing neuroblastoma cells (N2a) showed that the total membrane proteins reached a steady-state specific radioactivity in 18-20 h. However, examination of individual protein bands resolved by sodium dodecyl sulphate-urea-polyacrylamide-gel electrophoresis illustrated that differences in the kinetics of specific surface-membrane proteins could be detected. Although most of the protein bands reached a steady-state specific radioactivity at a time similar to that for total membrane proteins, at least two bands (mol. wt. 180000 and 130000) attained the steady-state within 8-10 h. It was shown by the use of dual-labelling techniques that these two protein bands turned over in the surface membranes of neuroblastoma N2a cells at least 180 and 150% faster than the total membrane protein. These two proteins were glycosylated and located on the outer surface of the cells, since they were labelled with radioactive carbohydrates and readily removed by treatment of the intact neuroblastoma cell with proteinases.


1981 ◽  
Vol 199 (3) ◽  
pp. 591-598 ◽  
Author(s):  
R J Beynon ◽  
J D Shannon ◽  
J S Bond

A metallo-endoproteinase was purified from mouse kidney. The enzyme was solubilized from the 100 000 g sediment of kidney homogenates with toluene and trypsin, and further purified by fractionation with (NH4)2SO4. DEAE-cellulose chromatography and gel filtration. The molecular weight of the metalloproteinase was estimated by gel filtration on Sepharose 6B to be 270 000--320 000. On sodium dodecyl sulphate/polyacrylamide-gel electrophoresis in the presence of 2-mercaptoethanol, a single major protein with a mol.wt. of 81 000 was observed. Thus the active enzyme is an oligomer, probably a tetramer. It is a glycoprotein and has an apparent isoelectric point of 4.3. Kidney homogenates and purified preparations of the metalloproteinase degraded azocasein optimally at pH 9.5 and at I 0.15--0.2. The activity was not affected by inhibitors of serine proteinases (di-isopropyl phosphorofluoridate, phenylmethanesulphonyl fluoride), cysteine proteinases (4-hydroxymercuribenzoate, iodoacetate), aspartic proteinases (pepstatin) or several other proteinase inhibitors from actinomycetes (leupeptin, antipain and phosphoramidon). Inhibition of the enzyme was observed with metal chelators (EDTA, EGTA, 1,10-phenanthroline), and thiol compounds (cysteine, glutathione, dithioerythritol, 2-mercaptoethanol). The metalloproteinase degraded azocasein, azocoll, casein, haemoglobulin and aldolase, but showed little or no activity against the synthetic substrates benzoylarginine 2-naphthylamide, benzoylglycylarginine, benzyloxycarbonylglutamyltyrosine or acetylphenylalanyl 2-naphthyl ester. This metalloproteinase from mouse kidney appears to be distinct from previously described kidney proteinases.


Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1574-1578 ◽  
Author(s):  
Hiraku Orita ◽  
Jun-ichi Sakai ◽  
Kenji Kubota ◽  
Mitsuru Okuda ◽  
Yuko Tanaka ◽  
...  

A new tobamo-like virus was isolated from a greenhouse-grown cucumber that showed severe mosaic distortion on leaves and fruit, in the southern part of Japan. The virus was tentatively designated Cucumber mottle virus (CuMoV) and further characterized. The size and antigenicity of the coat protein (CP) and the complete sequence of the genome were compared with those of the known cucurbit-infecting tobamoviruses: the W and SH strains of Cucumber green mottle mosaic virus (CGMMV), the C and Y strains of Kyuri green mottle mosaic virus (KGMMV), Cucumber fruit mottle mosaic virus (CFMMV), and Zucchini green mottle mosaic virus (ZGMMV). The CP of CuMoV migrated more slowly than those of CGMMV-W and -SH and KGMMV-C and -Y in sodium dodecyl sulfate polyacrylamide gel electrophoresis. In Western blot analysis, the CP of CuMoV cross-reacted weakly with antisera against CGMMV-W and did not react with antisera against KGMMV-Y. The overall nucleotide sequence of CuMoV had 62.5 to 63.5% identity with those of CGMMV-W, -SH, KGMMV-Y, CFMMV, and ZGMMV. The genome organization was characteristic of tobamoviruses, encoding a 131-kb protein, a 188-kb protein, a movement protein (MP), and CP in 5′ to 3′ order. In the phylogenetic analyses of the CP, CuMoV was placed in a separate lineage from CGMMV-W, -SH, KGMMV-C, -Y, CFMMV, and ZGMMV. The results indicate that CuMoV is a distinct tobamovirus species which represents a third sub-subgroup in the cucurbit-infecting tobamoviruses.


1986 ◽  
Vol 234 (2) ◽  
pp. 355-362 ◽  
Author(s):  
N H Sloane ◽  
W R Lynn ◽  
R M Macleod ◽  
E P K Hade ◽  
R Pottathil ◽  
...  

A fraction has been isolated from human urine which exhibits antiproliferative activity against human tumour cell lines without affecting the growth of several normal diploid cell lines or tumour cells of mouse or hamster origin. The major protein present in this fraction has been characterized and tentatively designated antineoplastic urinary protein (ANUP). An S020,W value of 3.69 S was obtained by sedimentation velocity analysis, and a subunit molecular mass of 16 300 Da was obtained by sedimentation equilibrium and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Centrifugation data also indicated that the protein self-associates. The amino acid analysis of ANUP was consistent with its low pI (4.2) as determined by chromatofocusing analysis. Furthermore, the amino acid composition exhibited some features similar to collagen, as shown by high levels of proline and glycine, the absence of cysteine, and the presence of low levels of hydroxyproline.


2007 ◽  
Vol 74 (3) ◽  
pp. 907-911 ◽  
Author(s):  
J. Jean-Gilles Beaubrun ◽  
M. H. Kothary ◽  
S. K. Curtis ◽  
N. C. Flores ◽  
B. E. Eribo ◽  
...  

ABSTRACT Outer membrane proteins (OMPs) expressed by Vibrio tubiashii under different environmental growth conditions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and PCR analyses. Results showed the presence of a 38- to 40-kDa OmpU-like protein and ompU gene, a maltoporin-like protein, several novel OMPs, and a regulatory toxR homolog.


1986 ◽  
Vol 64 (7) ◽  
pp. 1327-1330 ◽  
Author(s):  
David J. Gifford ◽  
C. C. Chinnappa

Seed proteins of Stellaria longipes s.l. 2n = 52, 78, and 104, have been characterized using sodium dodecyl sulphate – polyacrylamide gel electrophoresis. The same general pattern as regards the number of major protein components resolved was observed in all the genotypes and cytotypes studied. These included all the morphotypes that were described as distinct species. The present data do not contradict the conclusions drawn from cytogenetic studies that all the morphological types are closely related and are part of a polyploid species complex.


1974 ◽  
Vol 144 (3) ◽  
pp. 559-566 ◽  
Author(s):  
R H Brown ◽  
J M Lord ◽  
M J Merrett

1. Glyoxysomes and peroxisomes have been isolated from dark- and light-grown seedlings of pumpkin (Cucurbita pepo) by sucrose-density-gradient centrifugation. 2. Pumpkin microbodies and castor-bean (Ricinus communis) glyoxysomes may be fractionated, by a combination of osmotic shock and treatment with KCl, into three distinct groups of proteins: readily soluble (matrix enzymes), solubilized in the presence of KCl (membrane-bound enzymes) and relatively insoluble (membrane ‘ghost’ proteins). 3. Sodium dodecyl sulphate–polyacrylamide-gel electrophoresis of ‘ghost’ fractions indicated that the membrane proteins were generally of low molecular weight; one gel band (mol.wt. 27000–28000) was common to all three microbodies. 4. Although there were major differences in the soluble protein components of pumpkin glyoxysomes and peroxisomes, electrophoresis of the pumpkin microbody ‘ghosts’ indicated that the membrane proteins were similar, four main components being common to each class of microbody (monomer molecular weights 42000, 34000, 27000 and 17000).


1986 ◽  
Vol 34 (8) ◽  
pp. 1079-1084 ◽  
Author(s):  
A R Beaudoin ◽  
G Grondin ◽  
A Vachereau ◽  
P St-Jean ◽  
C Cabana

Small vesicles were visualized in the lumen of rat pancreas acini by freeze-substitution and conventional electron microscopy. Microvesicles were subsequently isolated from pancreatic juice. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that these vesicles contain only one major protein. The major protein was identified by an immunoblot technique as GP-2, an 80 kD glycoprotein also found in the zymogen granule membrane. The immunocytochemical localization of rabbit anti-GP-2 and anti-amylase by the protein A-gold technique confirmed that GP-2 was associated with clusters of microvesicles, whereas amylase was virtually excluded. Freeze-fracture of the microvesicles revealed that their membrane was devoid of intramembrane particles. Biochemical analysis indicated also that the membrane did not contain any detectable cholesterol. These results demonstrate that GP-2 is released from the acinar cell in the gland lumen within microvesicles by a hitherto undescribed mode of secretion.


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