scholarly journals Isolation and characterization of the vitelline layer of sea urchin eggs.

1977 ◽  
Vol 75 (2) ◽  
pp. 410-421 ◽  
Author(s):  
C G Glabe ◽  
V D Vacquier
Keyword(s):  
Sea Urchin ◽  
External Surface ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Internal Surface ◽  
Single Amino Acid ◽  
Sea Urchin Eggs ◽  
Isolation And Characterization ◽  
Triton X

The vitelline layers (VLs) of unfertilized sea urchin eggs were isolated by homogenization in a hypotonic medium containing Triton X-100 and EDTA. The surface topography of the VL is not changed by isolation. The thickness of the isolated VLs (300-400 A) is greater than that reported for VLs on intact eggs (100-200 A). Sperm adhere to the isolated VLs. When both internal and external VL surfaces are accessible to sperm, the sperm attach only to the external surface, suggesting that the external surface may carry sperm receptor proteins not present on the internal surface. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis shows that isolated VLs are composed of numerous proteins ranging from greater than 213,000 to 25,000 daltons. Lactoperoxidase-catalyzed 125I-iodination of unfertilized eggs labels two high molecular weight bands that stain faintly for carbohydrate. VLs are 90% protein and 3.5% carbohydrate. No predominance of a single amino acid or class of amino acids was found. Carbohydrate analysis yields fucose, mannose, galactose, glucose, xylose, glucosamine, galactosamine, and sialic acid. Controls for purity indicate that isolated VLs contain 2% protein of cytoplasmic origin and no more than 2.5% egg jelly.

Preparative isolation and characterization of the B875 complex from Rhodobacter sphaeroides 2.4.1

1988 ◽  
Vol 66 (5) ◽  
pp. 442-448 ◽  
Author(s):  
Rafael Picorel ◽  
Gabriel Gingras
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Phosphatidyl Ethanolamine ◽  
Sodium Dodecyl ◽  
Pigment Analysis ◽  
Preparative Isolation ◽  
Ethanolamine Phosphatidyl ◽  
Isolation And Characterization ◽  
Detergent System ◽  
Triton X

We have developed a simple and efficient method, using a mixed detergent system of sodium dodecyl sulfate and Triton X-100, for the preparative isolation of theB875 complex from Rhodobacter sphaeroides 2.4.1. As a bonus, the method allows the preparation of both the B875 and B800-850 complexes from the same batch of chromatophores. The preparations are spectrally pure, as indicated by absorption and circular dichroism spectroscopy. The latter method suggests that the Qy band of the B875 complex is due to weakly interacting bacteriochlorophyll molecules. Protein and pigment analysis shows that the B875 complex contains 2 mol of bacteriochlorophyll and 2 mol of sphaeroidene per mol of apoprotein (12 266 g), whereas the B800-850 complex contains 3 mol of bacteriochlorophyll and 1 mol of sphaeroidene per mol of apoprotein (11 497 g). While these stoichiometries are in accord with currently accepted models, they disagree with their published experimental basis. Phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol were found to be present in the B875 complex.

scholarly journals Isolation and characterization of human plasma α 1-proteinase inhibitor and a conformational study of its interaction with proteinases

1976 ◽  
Vol 157 (2) ◽  
pp. 339-351 ◽  
Author(s):  
J Saklatvala ◽  
G C Wood ◽  
D D White
Keyword(s):  
Human Plasma ◽  
Isoelectric Focusing ◽  
Proteinase Inhibitor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sedimentation Equilibrium ◽  
Isolation And Characterization ◽  
Step Procedure ◽  
Helical Content

1. alpha 1-Proteinase inhibitor was isolated from human plasma by a five-step procedure. Isoelectric focusing showed that six components focused between pH4.85 and 4.95. 2. The mol.wt. of the inhibitor was 52000 by sedimentation equilibrium and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The amino acid and carbohydrate compositions of the inhibitor were also determined. 3. The far-u.v.c.d. (circular-dichroism) spectrum indicated that the inhibitor had about 36% alpha-helical content. 4. The loss of proteinase-inhibitory activity when the inhibitor was exposed to pH values less than 5.0 or greater than 10.5 was accompanied by small changes in the far-u.v.c.d. spectrum and large changes in the near-u.v.c.d. spectrum. The change at alkaline pH was associated with ionization of tyrosine residues. 5. Interaction of inhibitor with chymotrypsin caused perturbation of the c.d. spectrum and this was used to follow the interaction and show a 1:1 stoicheiometry. 6. C.d., electrophoresis and isoelectric focusing showed that the inhibitor-enzyme complex is degraded by free enzyme. 7. Parallel studies with trypsin indicated that it too forms a 1:1 complex with inhibitor and is degraded by excess of enzyme.

Glycosylation of chicken haptoglobin: Isolation and characterization of three molecular variants and studies of their distribution in hen plasma before and after turpentine-induced inflammation

1988 ◽  
Vol 66 (3) ◽  
pp. 208-217 ◽  
Author(s):  
Francisco Delers ◽  
Gérard Strecker ◽  
Robert Engler
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Isolation And Characterization ◽  
Molecular Variants ◽  
Hemoglobin Binding ◽  
Significant Difference ◽  
Before And After ◽  
Carbohydrate Unit

Chicken haptoglobin (Hp), a hemoglobin-binding protein isolated from chicken plasma, is composed of three molecular variants that react differently with concanavalin A (ConA). These glycosylation variants of chicken Hp have been isolated by affinity chromatography using Sepharose-bound ConA. They differ in their molecular weight, as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Analysis of the glycopeptides obtained after pronase digestion of these variants yielded two types of structures: one, reactive with ConA, corresponded to a biantennary N-linked carbohydrate unit and one, unreactive with ConA, corresponded to a triantennary unit. The strongly ConA-reactive Hp variant bears only two biantennary units and the nonreactive Hp variant bears only two triantennary units; the weakly reactive Hp variant bears equal amounts of both units. The distribution of Hp glycosylation variant does not show any significant difference when obtained from the plasma of laying hens before and after turpentine-induced inflammation.

scholarly journals Functional Characterization of a Serine/Threonine Protein Kinase of Pseudomonas aeruginosa

1999 ◽  
Vol 67 (10) ◽  
pp. 5386-5394 ◽  
Author(s):  
S. Timothy Motley ◽  
Stephen Lory
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Catalytic Domain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Single Amino Acid ◽  
Migration Behavior

ABSTRACT Protein kinases play a key role in signal transduction pathways in both eukaryotic and prokaryotic cells. Using in vivo expression technology, we have identified several promoters in Pseudomonas aeruginosa which are preferentially activated during infection of neutropenic mice. One of these promoters directs the transcription of a gene encoding a putative protein kinase similar to the enzymes found in eukaryotic cells. The full characterization of this protein, termed PpkA, is presented in this communication. The ppkA gene encodes a 1,032-amino-acid polypeptide with an N-terminal catalytic domain showing all of the conserved residues of protein kinases with the substrate phosphorylation specificities for serine and threonine residues. The catalytic domain is linked to the rest of the protein by a short proline-rich segment. The enzymes showed anomalous migration behavior when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which could be attributed to autophosphorylation activity. The full-length enzyme was expressed as an oligohistidine fusion protein and was shown to phosphorylate several artificial protein substrates. Both autophosphorylation and phosphorylation of added substrates were strongly reduced by a single-amino-acid substitution in the catalytic domain of PpkA. Although PpkA appears to be differentially phosphorylated by autocatalysis, the levels of phosphorylation have minimal effect on its overall enzymatic activity. Our results, therefore, indicate the operation of a novel protein phosphorylation mechanism during transduction of signals in P. aeruginosa, and this pathway may be important in regulating the expression of virulence factors by this pathogen during certain phases of infection.

Timed photoaffinity labeling and characterization of bile acid binding and transport proteins in rat ileum

1993 ◽  
Vol 265 (1) ◽  
pp. G56-G62 ◽  
Author(s):  
M. C. Lin ◽  
E. Mullady ◽  
F. A. Wilson
Keyword(s):  
Bile Acid ◽  
Microsomal Fraction ◽  
Flash Photolysis ◽  
Basolateral Membrane ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Microsomal Protein ◽  
Bile Acid Binding ◽  
Triton X

Rat ileal enterocytes were radiolabeled by flash photolysis with a photolabile derivative of taurocholate (7,7-azo-[3H]TC) and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Maximal labeling of the bile acid binding proteins (BABPs) was achieved between 15 and 90 s. When enterocytes were pulsed with 7,7-azo-[3H]TC for 2 min, and then 0.5 mM TC was added to chase the radiolabel, the radioactivity in the BABPs was displaced by 50% after 2 min. The 99-kDa brush-border membrane (BBM) protein had the highest initial labeling rate, followed by 43-kDa actin, 35- and 14-kDa cytosolic proteins, 54-kDa basolateral membrane (BLM) protein, 59-kDa BLM-associated protein, and 20-kDa microsomal protein. When a mixed microsomal and cytosolic fraction was photolabeled with 7,7-azo-[3H]TC and then separated, the 20-kDa microsomal protein was labeled. However, if the microsomal fraction alone was photolabeled, the 20-kDa protein was not labeled, suggesting this protein required a cytosolic cofactor for labeling. Using Triton X-114 phase separation and EDTA extraction, the BABPs were separated into amphiphilic integral membrane proteins (99- and 54-kDa proteins) and hydrophilic proteins (14-, 35-, 43-, and 59-kDa proteins). From these data, a model is proposed for transcellular bile acid transport in rat ileal enterocytes.

scholarly journals Isolation and characterization of lung connective-tissue glycoproteins

1982 ◽  
Vol 203 (3) ◽  
pp. 593-601 ◽  
Author(s):  
C Lafuma ◽  
M Moczar ◽  
L Robert
Keyword(s):  
Proteinase Inhibitors ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Lung Parenchyma ◽  
Isolation And Characterization ◽  
Isoelectric Points ◽  
And Function

1. Glycoproteins of hamster, rat and baboon lung parenchyma were investigated by using [14C]glucosamine incorporation in vitro followed by sequential extraction of the macromolecular components and characterization of the glycoproteins in the extracts. 2. Slices of lung parenchyma maintained in vitro incorporated [U-14C]glucosamine linearly with time into non-diffusible macromolecules for up to 5h. All the macromolecule-associated 14C label was present as [14C]glucosamine. 3. These 14C-labelled macromolecules were extracted from previously delipidated and salt-extracted lung by 5M-guanidinium chloride in the presence of dithiothreitol and proteinase inhibitors before (extract A1) and after (extract A2) hydrolysis of the collagen by collagenase. The [14C]glucosamine-labelled glycoproteins in extracts A1 and A2 contained 55 and 5% respectively of the total [14C]glucosamine incorporated in the lung of all three species studied. 4. The [14C]glucosamine-labelled glycoproteins were analysed by gel-filtration chromatography, sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectric focusing. The major [14C]glucosamine-labelled glycoproteins of baboon lung parenchyma had apparent mol.wts. of about 400 000, 140 000 and 65 000 with isoelectric points respectively of 4.8, 5.4 and 5.4. The hamster lung glycoproteins with isoelectric points of 4.1 and 5.8 were devoid of hydroxyproline and contained galactose, mannose and N-acetylglucosamine. These experiments indicate that several distinct glycoproteins are synthesized in situ by the cells of pulmonary parenchyma and may well play a role in its structure and function.

scholarly journals Isolation and characterization of desmosome-associated tonofilaments from rat intestinal brush border.

1981 ◽  
Vol 90 (1) ◽  
pp. 116-127 ◽  
Author(s):  
W W Franke ◽  
S Winter ◽  
C Grund ◽  
E Schmid ◽  
D L Schiller ◽  
...  
Keyword(s):  
Small Intestine ◽  
Brush Border ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Two Dimensional Gel Electrophoresis ◽  
Ph Values ◽  
Isolation And Characterization ◽  
Isoelectric Ph ◽  
Triton X

Epithelial cells of the small intestine, like those of other internal organs, contain intermediate-sized filaments immunologically related to epidermal prekeratin which are especially concentrated in the cell apex. Brush-order fractions were isolated from rat small intestine, and apical tonofilaments attached to desmosomal plaques and terminal web residues were prepared therefrom by extraction in high salt (1.5 M KCl) buffer and Triton X-100. The structure of these filaments was indistinguishable from that of epidermal tonofilaments and, as with epidermal prekeratin, filaments could be reconstituted from solubilized, denatured intestinal tonofilament protein. On SDS polyacrylamide gel electrophoresis of proteins of the extracted desmosome-tonofilament fractions, a number of typical brush-border proteins were absent or reduced, and enrichment of three major polypeptides of Mr 55,000, 48,000, and 40,000 was noted. On two-dimensional gel electrophoresis, the three enriched major polypeptides usually appeared as pairs of isoelectric variants, and the two smaller components (Mr 48,000, and 40,000) were relatively acidic (isoelectric pH values of 5.40 and below), compared to the Mr 55,000 protein which focused at pH values higher than 6.4. The tonofilament proteins were shown to be immunologically related to epidermal prekeratin by immunoreplica and blotting techniques using antibodies to bovine epidermal prekeratins. Similar major polypeptides were found in desmosome-attached tonofilaments from small intestine of mouse and cow. However, comparisons with epidermal tissues of cow and rat showed that all major polypeptides of intestinal tonofilaments were different from the major prekeratin polypeptides of epidermal tonofilaments. The results present the first analysis of a defined fraction of tonofilaments from a nonepidermal cell. The data indicate that structurally identical tonofilaments can be formed, in different types of cells, by different polypeptides of the cytokeratin family of proteins and that tonofilaments of various epithelia display tissue-specific patterns of their protein subunits.

scholarly journals Purification and immunochemical characterization of monoamine oxidase from rat and human liver

1977 ◽  
Vol 161 (1) ◽  
pp. 167-174 ◽  
Author(s):  
R G Dennick ◽  
R J Mayer
Keyword(s):  
Enzyme Activity ◽  
Monoamine Oxidase ◽  
Enzyme Activities ◽  
Gel Electrophoresis ◽  
Human Liver ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Triton X

1. Monoamine oxidase from rat and human liver was purified to homogeneity by the criterion of polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. 2. The enzyme activity was extracted from mitochondrial preparations by Triton X-100. The enzyme was purified by (NH4)2SO4 fractionation followed by chromatography on DEAE-cellulose, Sepharose 6B, spheroidal hydroxyapatite, and finally chromatography on diazo-coupled tyramine-Sepharose. 3. Distinct differences occur in the chromatographic behaviour of the two enzymes on both DEAE-cellulose and spheroidal hydroxyapatite. 4. It is unlikely that the purification of the enzymes on tyramine-Sepharose is due to affinity chromatography and reasons for this are discussed. 5. The purified enzymes did not oxidize-5-hydroxytryptamine and the relative activities of the enzymes with benzylamine were increased approx. 1.25-fold compared with the enzyme activities of mitochondrial preparations. 6. Immunotitration of enzyme activity in extracts of mitochondrial preparations from rat liver was carried out with 5-hydroxytryptamine, tyramine and benzylamine. The enzyme activities were completely immunoprecipitated by the same volume of antiserum. Similar results were obtained with the antiserum to the enzyme from human liver.

Isolation and characterization of goat serum α1-globulin protease inhibitors

1982 ◽  
Vol 60 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Albert Hercz
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Protease Inhibitors ◽  
Isoelectric Focusing ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Isolation And Characterization ◽  
Sds Page

α1-Globulin-type protease inhibitors were isolated from goat serum by two methods, namely preparative isoelectric focusing and preparative electrophoresis in polyacrylamide gel. The fractions obtained by the first method showed varying isoprotein compositions by analytical isoelectric focusing. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) revealed the presence of one protein in the fractions with the same velocity of migration as purified human α1-antitrypsin and a second protein with a slightly higher migration velocity. The ratios of trypsin-inhibiting to chymotrypsin-inhibiting capacities in all the fractions were the same and both inhibitors were stable upon storage. The reaction of the inhibitors with trypsin and chymotrypsin was also demonstrated by analytical isoelectric focusing.The fractions obtained by preparative gel electrophoresis (the second method) contained the same proteins but their proportions varied widely in different fractions as demonstrated by analytical electrofocusing in the presence of urea and by SDS–PAGE. The early fractions, which consisted predominantly of α1-antitrypsin, showed a high inhibiting capacity for trypsin and none or only negligible capacity for chymotrypsin. Conversely, in the late fractions, the proportions of the proteins and inhibiting capacities were reversed. At 4 °C the trypsin-inhibiting capacity was stable for weeks but the chymotrypsin-inhibiting capacity of the preparation rapidly decreased.These observations indicate that the inhibition of proteases by goat α1-globulins is due to at least two closely associated but distinguishable proteins. One of these, corresponding to human α1-antitrypsin, would have an appreciable capacity to inhibit trypsin, but unlike the latter, little or no capacity for chymotrypsin inhibition. The inhibition of chymotrypsin is due to the second, unidentified α1-globulin.

Isolation and characterization of cancer-associated galactosyltransferase isoenzyme.

1984 ◽  
Vol 30 (10) ◽  
pp. 1656-1663 ◽  
Author(s):  
B P Ram ◽  
D D Munjal
Keyword(s):  
Cancer Patient ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Isolation And Characterization ◽  
Absolute Requirement ◽  
Triton X ◽  
Alpha Lactalbumin

Abstract We isolated galactosyltransferase (EC 2.4.1.22) from pleural effusions of a lung cancer patient and a patient with cirrhosis by precipitation with ammonium sulfate, followed by gel filtration on Sepharose 6B, and affinity chromatography on columns of alpha-lactalbumin-agarose and protein A-Sepharose. By this procedure the enzyme from both sources was purified 40 000-fold with approximate yields of 37% and 60%, respectively, and did not contain immunoglobulin. Electrophoresis on polyacrylamide gel of the enzyme from the cancer patient (slower moving) and from the non-cancer patient (faster moving) gave one sharp band for each. Their respective relative molecular masses, 74 131 and 107 151, were estimated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and gel filtration, respectively. The isoenzymes were active between pH 5 and 8, most active at 7, and showed no activity below pH 4 or above pH 9. Activity was greatest at temperatures between 37 and 40 degrees C. At 30 degrees C or 50 degrees C the activity was more than halved, and was lost completely above 60 degrees C. The isoenzymes had an absolute requirement for Mn2+. Omitting the surfactant Triton X-100 from the buffer resulted in considerable loss in activity of both isoenzymes. Glucose can be used as an acceptor for these isoenzymes if alpha-lactalbumin is present in the assay mixture. These isoenzymes had different Km values for UDP-galactose, N-acetylglucosamine, and Mn2+.

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