scholarly journals CHEMICAL CHARACTERIZATION OF ISOLATED EPIDERMAL DESMOSOMES

1974 ◽  
Vol 63 (2) ◽  
pp. 524-530 ◽  
Author(s):  
Christine J. Skerrow ◽  
A. Gedeon Matoltsy

Desmosomes, isolated from cow nose epidermis by a method utilizing citrate buffer pH 2.6 and density gradient centrifugation, have been analyzed and found to contain approximately 76% protein, 17% carbohydrate, and 10% lipid. Nonpolar amino acids predominate in desmosomal protein, representing 456 residues per 1,000. The sialic acid content is 5 nM/mg of protein. The lipid fraction is composed of approximately 40% cholesterol and 60% phospholipids. Desmosomes are completely solubilized by incubation with 2% sodium dodecyl sulphate and 1% ß-mercaptoethanol. Gel electrophoresis of the denatured desmosomal proteins reveals 24 bands, with mobilities corresponding to a molecular weight range of 15,000–230,000 daltons. Seven of these are considered to be major bands, together constituting 81% of the desmosomal protein. Bands 1 and 2, of molecular weights 230,000 and 210,000 daltons, together comprise 28% by weight of the desmosome. It is suggested that these protein chains are located in the desmosomal plaque. Bands 3 and 4 are PAS-positive, constitute 23% of the desmosomal protein, and have apparent molecular weights of 140,000 and 120,000 daltons, respectively. At least part of this material must originate from the carbohydrate-containing layer which is demonstrated, by histochemistry, to be present in the desmosomal interspace. The possible nature and origin of the remaining major bands, of molecular weights 90,000, 75,000, and 60,000 daltons, are discussed.

Author(s):  
Ruchama Baum ◽  
J.T. Seto

The ribonucleic acid (RNA) of paramyxoviruses has been characterized by biochemical and physiochemical methods. However, paramyxovirus RNA molecules have not been studied by electron microscopy. The molecular weights of these single-stranded viral RNA molecules are not known as yet. Since electron microscopy has been found to be useful for the characterization of single-stranded RNA, this investigation was initiated to examine the morphology and length measurements of paramyxovirus RNA's.Sendai virus Z strain and Newcastle disease virus (NDV), Milano strain, were used. For these studies it was necessary to develop a method of extracting RNA molecules from purified virus particles. Highly purified Sendai virus was treated with pronase (300 μg/ml) at 37°C for 30 minutes and the RNA extracted by the sodium dodecyl sulfate (SDS)-phenol procedure.


2000 ◽  
Vol 66 (1) ◽  
pp. 252-256 ◽  
Author(s):  
Katsuichi Saito ◽  
Kazuya Kondo ◽  
Ichiro Kojima ◽  
Atsushi Yokota ◽  
Fusao Tomita

ABSTRACT Streptomyces exfoliatus F3-2 produced an extracellular enzyme that converted levan, a β-2,6-linked fructan, into levanbiose. The enzyme was purified 50-fold from culture supernatant to give a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights of this enzyme were 54,000 by SDS-PAGE and 60,000 by gel filtration, suggesting the monomeric structure of the enzyme. The isoelectric point of the enzyme was determined to be 4.7. The optimal pH and temperature of the enzyme for levan degradation were pH 5.5 and 60°C, respectively. The enzyme was stable in the pH range 3.5 to 8.0 and also up to 50°C. The enzyme gave levanbiose as a major degradation product from levan in an exo-acting manner. It was also found that this enzyme catalyzed hydrolysis of such fructooligosaccharides as 1-kestose, nystose, and 1-fructosylnystose by liberating fructose. Thus, this enzyme appeared to hydrolyze not only β-2,6-linkage of levan, but also β-2,1-linkage of fructooligosaccharides. From these data, the enzyme from S. exfoliatus F3-2 was identified as a novel 2,6-β-d-fructan 6-levanbiohydrolase (EC 3.2.1.64 ).


1986 ◽  
Vol 64 (7) ◽  
pp. 638-646 ◽  
Author(s):  
Peter C. Loewen ◽  
Jacek Switala

Catalase (hydroperoxidase II or HPII) of Escherichia coli K12 has been purified using a protocol that also allows the purification of the second catalase HPI in large amounts. The purified HPII was found to have equal amounts of two subunits with molecular weights of 90 000 and 92 000. Only a single 92 000 subunit was present in the immunoprecipitate created when HPII antiserum was added directly to a crude extract, suggesting that proteolysis was responsible for the smaller subunit. The apparent native molecular weight was determined to be 532 000, suggesting a hexamer structure for the enzyme, an unusual structure for a catalase. HPII was very stable, remaining maximally active over the pH range 4–11 and retaining activity even in a solution of 0.1% sodium dodecyl sulfate and 7 M urea. The heme cofactor associated with HPII was also unusual for a catalase, in resembling heme d (a2) both spectrally and in terms of solubility. On the basis of heme-associated iron, six heme groups were associated with each molecule of enzyme or one per subunit.


1977 ◽  
Vol 73 (2) ◽  
pp. 382-399 ◽  
Author(s):  
J S Caruthers ◽  
M A Bonneville

The lumenal plasma membrane has been isolated from transitional epithelial cells (urothelium) lining the urinary bladder in sheep by a modified technique involving treatment with hypotonic thioglycolate. The isolated membranes, like those in situ, are distinguished morphologically by arrays of hexagonal particles (in plague regions) separated by smooth interplaque regions. These plaque regions, specifically, can be isolated from the lumenal plasma membrane. Of the proteins constituting the lumenal plasma membrane, five were found to characterize the plaque regions and, in particular, the 33,000-dalton species appears to be most heavily concentrated in the sodium dodecyl sulfate-polyacrylamide gel pattern of the isolated plaque regions. Lipid analyses showed that there are approximately 0.93 mg of phospholipid and 0.27 mg of cholesterol for each milligram of protein, giving a value of 55% lipids and 45% proteins for the composition of the lumenal plasma membrane. The total sialic acid content was measured to be approximately 0.038 micronmol/mg protein for the plasma membrane. Several plasma membrane marker enzymes were found to be associated with the lumenal plasma membrane fraction, but only the 5'-nucleotidase activity was found to be further enriched in the plaque region fraction. Amino acid analysis of the intrinsic proteins of the plaques indicated a polarity index of 45%.


1983 ◽  
Vol 29 (10) ◽  
pp. 1361-1368 ◽  
Author(s):  
Thomas P. Poirier ◽  
Stanley C. Holt

Capnocytophaga ochracea acid (AcP; EC 3.1.3.2) and alkaline (AlP; EC 3.1.3.1) phosphatase was isolated by Ribi cell disruption and purified by sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE.) Both phosphatases eluted from Sephadex G-150 consistent with molecular weights (migration) of 140 000 and 110 000. SDS–PAGE demonstrated a 72 000 and 55 000 subunit molecular migration for AcP and AlP, respectively. The kinetics of activity of purified AcP and AIP on p-nitrophenol phosphate and phosphoseryl residues of the phosphoproteins are presented.


1984 ◽  
Vol 62 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Lilian Lee ◽  
Gordon Forstner

Failure to develop clear-cut, distinguishing characteristics for hydrophobic and hydrophilic forms of maltase–glucoamylase led us to attempt the purification of the detergent-extracted enzyme in the continuous presence of protease inhibitors (phenylmethylsulfonyl fluoride and N-ethylmaleimide). The enzyme was purified by molecular exclusion, anion-exchange, and affinity column chromatography to a final specific maltase activity of 80 U/mg protein, comparable to previously solubilized enzymes. Both detergent (d-maltase) and proteolytically (p-maltase) solubilized enzymes had identical Km's for maltose and similar glycogenase activity. d-Maltase was clearly amphipathic. Whereas 95% of p-maltase was eluted with aqueous buffer from an octyl-Sepharose CL-4B column, the elution of d-maltase required solutions containing Triton X-100 and ethylene glycol. On density gradient centrifugation and sodium dodecyl sulfate (SDS) – polyacrylamide gels, p-maltase migrated as one high molecular weight species of 500 000. In contrast d-maltase migrated heterogeneously and the smallest maltase-active forms delineated by these two techniques, as well as by high pressure liquid chromatography, had molecular weights which ranged from 120 000 to 150 000. Both p- and d-maltase were dissociated by heat in SDS, forming five prominent species as we have previously described. In contrast to p-maltase, in which the smallest species, band 1, equalled 36.7% of the total mass, band 1 of d-maltase accounted for 66.5%. Band 1 was separable when smaller amounts of enzyme were applied to slab gels and stained with silver, into two proteins of 130 000 and 145 000 daltons. The 145 000 dalton protein was absent in p-maltase and was replaced by a faint band of 140 000 daltons. The 140 000 dalton band, plus a new N-terminal glycine, were also generated from d-maltase during prolonged storage at −20 °C. These data suggest that rat intestinal maltase–glucoamylase contains two monomeric proteins. The largest monomer contains an additional peptide segment at the N-terminus, which is removed by proteolysis and presumably anchors the enzyme to the microvillus membrane. After removal from the membrane, the two monomers of the d-enzyme are apparently partially dissociated to account for maltase activity within the 120 000 to 150 000 dalton range. Conversely, removal of the anchor segment favours a polymeric structure.


2001 ◽  
Vol 183 (24) ◽  
pp. 7037-7043 ◽  
Author(s):  
Akihiko Kosugi ◽  
Koichiro Murashima ◽  
Roy H. Doi

ABSTRACT Xylanase activity of Clostridium cellulovorans, an anaerobic, mesophilic, cellulolytic bacterium, was characterized. Most of the activity was secreted into the growth medium when the bacterium was grown on xylan. Furthermore, when the extracellular material was separated into cellulosomal and noncellulosomal fractions, the activity was present in both fractions. Each of these fractions contained at least two major and three minor xylanase activities. In both fractions, the pattern of xylan hydrolysis products was almost identical based on thin-layer chromatography analysis. The major xylanase activities in both fractions were associated with proteins with molecular weights of about 57,000 and 47,000 according to zymogram analyses, and the minor xylanases had molecular weights ranging from 45,000 to 28,000. High α-arabinofuranosidase activity was detected exclusively in the noncellulosomal fraction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that cellulosomes derived from xylan-, cellobiose-, and cellulose-grown cultures had different subunit compositions. Also, when xylanase activity in the cellulosomes from the xylan-grown cultures was compared with that of cellobiose- and cellulose-grown cultures, the two major xylanases were dramatically increased in the presence of xylan. These results strongly indicated that C. cellulovorans is able to regulate the expression of xylanase activity and to vary the cellulosome composition depending on the growth substrate.


1981 ◽  
Vol 199 (1) ◽  
pp. 145-154 ◽  
Author(s):  
P E Bowden ◽  
W J Cunliffe

The polypeptide-chain components of human epidermal prekeratin and keratin were analysed by high-resolution SDS (sodium dodecyl sulphate)/polyacrylamide-gradient-gel electrophoresis. Size heterogeneity existed amongst prekeratin components and at least ten polypeptides, in the molecular-weight range 46,000-70,000, were observed in 0.1 M-citric acid/sodium citrate buffer (pH 2.65) extracts of scale epidermis. Prekeratin from scalp pilosebaceous ducts was identical with that from the contiguous epidermis, and no prekeratin was found in extracts of scale dermis. Prekeratin from plantar epidermis contained additional polypeptide chains, but only slight anatomical variation existed between the non-callus sites examined. Keratin differed from prekeratin in at least two major respects: (a) many major components did not co-electrophorese on high-resolution SDS/polyacrylamide slab gels, and (b) keratin, but not prekeratin, required denaturing and reducing conditions for extraction. Keratin extracted from scale epidermis after complete removal of prekeratin was identical with forearm stratum-corneum keratin. Palmar and plantar keratin contained additional polypeptide chains and had a different size distribution compared with forearm and scalp keratin components. Modification of prekeratin components to produce the keratin polypeptide profile occurred during epidermal differentiation, and these changes appeared to take place in the granular-layer region of the epidermis.


Author(s):  
David Arturo-Perdomo ◽  
Juan Pablo Jiménez Mora ◽  
Elena Ibáñez ◽  
Alejandro Cifuentes ◽  
Andrés Hurtado-Benavides ◽  
...  

AbstractThe study of the phytochemical composition of seed oils is of upmost importance for the food and cosmetic industries, mainly considering their associated biological properties. Extraction of seed oils using supercritical fluids (SFE) is an ecological and green alternative to conventional extraction processes since it is able to provide with potent bioactive extracts, avoiding degradation and transformation of the compounds present originally in the raw material. The objective of the present work was the extraction of pure fractions of polar lipids and their chemical characterization using chromatographic techniques such as GC-MS and LC-DAD-MS/MS of blackberry (Rubus glaucus) and passion fruit (Passiflora edulis) seed oils extracted by supercritical carbon dioxide. Oleamides derived from oleic acid were identified as the main compounds in both samples; in particular, 9-octadecenamide was the major identified oleamide. Besides, the extract obtained from passion fruit showed to be a source of linoleic acid, while the SFE extract from blackberry presented important concentrations of vanillin. The chemical composition of these seed oils can be of high interest for their further use in cosmetics and food industry.


1975 ◽  
Vol 2 (1) ◽  
pp. 13 ◽  
Author(s):  
RJ Blagrove ◽  
JM Gillespie

The three globulins of the seeds of L. angustifolius cv. Uniwhite may be satisfactorily resolved in 10 min by electrophoresis on cellulose acetate strips. These globulins, conglutins α, β and γ, vary markedly in their amino acid compositions, with conglutin Ω differing from conglutins α and β and most other legume storage proteins in its relatively high content of cystine and methionine and lower content of arginine and glutamic acid. When examined on sodium dodecyl sulphate-polyacrylamide gels, both in the absence and presence of β-mercaptoethanol, the three globulins were found to differ completely in the type of subunit proteins they contain and in the significance of intrachain disulphide bonding. Conglutin α was found to contain three or four types of non-covalently linked subunits with apparent molecular weights in the range 55 000-80 000, each of which may contain a disulphide-bonded moiety with a molecular weight near 20 000. Conglutin γ was found to contain disulphide-bonded chains of molecular weights 17 000 and 30 000, whereas the four major subunits of conglutin β, whose molecular weights lie in the range 20 000-60 000, were not covalently linked together. The latter globulin does not appear to be homogeneous, for it can be separated by fractional precipitation with ammonium sulphate into a series of fractions which differ markedly in the proportion of subunit types they contain.


Sign in / Sign up

Export Citation Format

Share Document