scholarly journals Human C4-binding protein. I. Isolation and characterization

1978 ◽  
Vol 148 (1) ◽  
pp. 207-222 ◽  
Author(s):  
J Scharfstein ◽  
A Ferreira ◽  
I Gigli ◽  
V Nussenzweig
Keyword(s):  
Complement System ◽  
Binding Protein ◽  
Divalent Cations ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Electrophoretic Patterns ◽  
Isolation And Characterization ◽  
Sds Page ◽  
Edta Plasma ◽  
The Complement System

C4-binding protein (C4-bp), a new component of the complement system, was isolated from human plasma by precipitation with polyethyleneglycol, followed by chromatography on ion exchangers. C4-bp was identified on sodium dodecyl- sulfate polyacrylamide gel electrophoresis (SDS-PAGE) by two independent criteria: its ability to bind to C4b, and immunoprecipitation with a monospecificantiserum. Purified C4-bp is a 10.7 s glycoprotein. It consists of several disulfide bonded subunits of mol wt 70,000 daltons. Under nonreducing conditions, its mol wt has been estimated on SDS-PAGE as 540- 590,000 daltons. C4-bp moves as a slow B-globulin at pH 8.6 in the absence of free divalent cations, but when the buffers contain Ca(++)-lactate, C4-bp is a gamma globulin. Purified C4-bp binds to purified C4b. The reaction proceeds in the presence or absence of divalent cations and is not inhibited by diisopropylfluorophosphate. The C4b/C4-bp complexes have sedimentation coefficients between 15 and 17 s on sucrose gradient ultracentrifugation, and can be readily identified by crossed immunoelectrophoresis (CIE). The complexes move faster toward the anode than either protein. C4-bp is multivalent. Saturation is reached at molecular ratios of C4b/C4- bp of between 4 and 5. The interaction between C4b and C4-bp may complicate the electrophoretic patterns of these proteins in normal human serum, if the complement system is activated before or during the run. However, in EDTA-plasma, native C4 and C4-bp do not form stable complexes and can be identified in separate peaks after CIE.

scholarly journals Isolation and Characterization of Two Proteins fromMoraxella catarrhalis That Bear a Common Epitope

1998 ◽  
Vol 66 (9) ◽  
pp. 4374-4381 ◽  
Author(s):  
John C. McMichael ◽  
Michael J. Fiske ◽  
Ross A. Fredenburg ◽  
Deb N. Chakravarti ◽  
Karl R. VanDerMeid ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Bacterial Attachment ◽  
Vaccine Candidates ◽  
Isolation And Characterization ◽  
Sds Page

ABSTRACT The UspA1 and UspA2 proteins of Moraxella catarrhalisare potential vaccine candidates for preventing disease caused by this organism. We have characterized both proteins and evaluated their vaccine potential using both in vitro and in vivo assays. Both proteins were purified from the O35E isolate by Triton X-100 extraction, followed by ion-exchange and hydroxyapatite chromatography. Analysis of the sequences of internal peptides, prepared by enzymatic and chemical cleavage of the proteins, revealed that UspA1 and UspA2 exhibited distinct structural differences but shared a common sequence including an epitope recognized by the monoclonal antibody 17C7. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), purified UspA1 exhibited a molecular weight of approximately 350,000 when unheated and a molecular weight of 100,000 after being heated for 10 min at 100°C. In contrast, purified UspA2 exhibited an apparent molecular weight of 240,000 by SDS-PAGE that did not change with the length of time of heating. Their sizes as determined by gel filtration were 1,150,000 and 830,000 for UspA1 and UspA2, respectively. Preliminary results indicate the proteins have separate functions in bacterial pathogenesis. Purified UspA1 was found to bind HEp-2 cells, and sera against UspA1, but not against UspA2, blocked binding of the O35E isolate to the HEp-2 cells. UspA1 also bound fibronectin and appears to have a role in bacterial attachment. Purified UspA2, however, did not bind fibronectin but had an affinity for vitronectin. Both proteins elicited bactericidal antibodies in mice to homologous and heterologous disease isolates. Finally, mice immunized with each of the proteins, followed by pulmonary challenge with either the homologous or a heterologous isolate, cleared the bacteria more rapidly than mock-immunized mice. These results suggest that UspA1 and UspA2 serve different virulence functions and that both are promising vaccine candidates.

Identification of the Poly(C) Binding Protein in the Complex Associated With the 3′ Untranslated Region of Erythropoietin Messenger RNA

Blood ◽  
1999 ◽  
Vol 93 (6) ◽  
pp. 2111-2120 ◽  
Author(s):  
Maria F. Czyzyk-Krzeska ◽  
Amy C. Bendixen
Keyword(s):  
Mrna Stability ◽  
Messenger Rna ◽  
Untranslated Region ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Mobility Shift ◽  
Protein Factor ◽  
Ribonucleoprotein Complexes ◽  
Sds Page

Hypoxia regulates expression of erythropoietin (EPO), a glycoprotein that stimulates erythrocytosis, at the level of transcription and also possibly at the level of messenger RNA (mRNA) stability. A pyrimidine-rich region within the EPO mRNA 3′ untranslated region was implicated in regulation of EPO mRNA stability element and shown to bind protein factors. In the present study we wished to identify the protein factor binding to the pyrimidine-rich sequence in the EPO mRNA stability element. Using mobility shift assays, ultraviolet light cross-linking, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and electroelution of protein factors from the gel slices corresponding to the ribonucleoprotein complexes, we found that two isoforms of a 40 kD poly(C) binding protein (PCBP, also known as CP or hnRNPE), PCBP1, and PCBP2 are present in that complex. In Hep3B or HepG2 cells hypoxia induces neither expression of PCBP nor formation of the ribonucleoprotein complex associated with EPO mRNA that involves PCBP.

scholarly journals Specific and azurophilic granules from rabbit polymorphonuclear leukocytes. I. Isolation and characterization of membrane and content subfractions.

1983 ◽  
Vol 96 (4) ◽  
pp. 1030-1039 ◽  
Author(s):  
W J Brown ◽  
W A Shannon ◽  
W J Snell
Keyword(s):  
Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Granule Protein ◽  
Isolation And Characterization ◽  
Cytoplasmic Face ◽  
Sds Page ◽  
Granule Membrane ◽  
Granule Membrane Proteins

The specific and azurophilic granules of rabbit polymorphonuclear heterophils (PMNs) have been isolated and fractionated into membrane and extractable subfractions. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) revealed several features of the protein composition of the two granules: (a) Whereas each type of granule had 40-60 proteins separable on one-dimensional gradient gels, few of the proteins were common to both granules. (b) The proteins of the extractable fractions (which comprised approximately 98% of the total granule protein) of each granule were distinct from the proteins of the membrane fractions (which comprised approximately 2% of the total granule protein). (c) The extractable proteins co-migrated with those collected from the medium of ionophore-treated, degranulating PMNs and therefore were defined as content proteins. These results were confirmed by radiolabeling studies. Lactoperoxidase-catalyzed iodination of intact granules did not label the content proteins but did label proteins that co-migrated with major granule membrane proteins. Moreover, disruption of the granules before iodination led to labeling of both content and membrane proteins. We conclude that the membranes of specific and azurophilic granules, which arise from different faces of the Golgi complex, are composed of unique sets of membrane proteins some of which are exposed on the cytoplasmic face of the granules.

Distinct regional localization of neurocalcin, a Ca2+-binding protein, in the bovine adrenal gland

1993 ◽  
Vol 138 (2) ◽  
pp. 283-NP ◽  
Author(s):  
A. Nakano ◽  
M. Terasawa ◽  
M. Watanabe ◽  
K. Okazaki ◽  
S. Inoue ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Dissociation Constant ◽  
Adrenal Medulla ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Physiological Role ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
Sds Page

ABSTRACT Neurocalcin (molecular weight 23 000 and 24 000) is a Ca2+-binding protein with three putative Ca2+-binding domains and is present in large amounts in nervous tissues. Neurocalcin isoproteins separated by C18 reverse-phase column chromatography are insoluble in buffer solution and it is impossible to determine the dissociation constant of neurocalcin with Ca2+. To overcome this difficulty, recombinant neurocalcin was synthesized, based on one of the cDNAs of the neurocalcin isoproteins. Stoichiometric titration experiments, using recombinant neurocalcin, indicated that this protein bound 2 mol Ca2+/mol protein and that the apparent dissociation constant for Ca2+ was 2·2 μmol/l, suggesting that neurocalcin plays a physiological role in cellular function. Immunoblotting showed that neurocalcin is present in the bovine adrenal gland in addition to the nervous tissues. Neurocalcin, identified by immunoblotting, was purified from the bovine adrenal gland. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of neurocalcin from the bovine brain showed 23 kDa and 24 kDa double bands, while SDS-PAGE of neurocalcin from the adrenal gland showed a single band of apparently 24 kDa, suggesting that the expression of neurocalcin isoproteins differs from tissue to tissue. The content of neurocalcin in the adrenal gland was 10 μg protein/100 g wet tissue. Immunohistochemical analysis showed the occurrence of neurocalcin in zona glomerulosa and adrenal medulla but not in zona fasciculata or zona reticularis. The restricted localization of neurocalcin in the adrenal gland suggests that a similar Ca2+ signal pathway may be present in zona glomerulosa and the adrenal medulla. Journal of Endocrinology (1993) 138, 283–290

Effective pretreatment by cysteine proteinase inhibitor for improved analysis of protein components of trematodes on SDS-PAGE

1990 ◽  
Vol 64 (3) ◽  
pp. 175-179 ◽  
Author(s):  
M. Itoh ◽  
S. Sato ◽  
A. Moriyama ◽  
M. Sasaki
Keyword(s):  
Proteinase Inhibitor ◽  
Cysteine Proteinase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Clonorchis Sinensis ◽  
Sodium Dodecyl ◽  
Heating Process ◽  
Cysteine Proteinase Inhibitor ◽  
Electrophoretic Patterns ◽  
Sds Page ◽  
Protein Components

ABSTRACTSince Fasciola sp. contained proteolytic enzyme(s), it was confirmed that degradation took place in protein components in extracts of the liver flukes, which resulted in lack of clarity of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Degradation was shown to occur mostly during a heating process of the extract samples. The proteolytic activity in the extracts was completely blocked and electrophoretic patterns were improved only by the use of cysteine proteinase inhibitor N-[N-(L-3-trans-carboxyoxiran-2-carbonyl)-L-leucyl]-agmatine (E-64). Great improvement was also noted in electrophoretic patterns of the extracts of other trematodes, such as Paragonimus westermani, P. miyazakii and Clonorchis sinensis, when their extracts were treated with E-64.

scholarly journals Isolation and characterization of riboflavin-binding protein from pregnant-rat serum

1980 ◽  
Vol 187 (2) ◽  
pp. 537-540 ◽  
Author(s):  
K Muniyappa ◽  
P R Adiga
Keyword(s):  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Disc Electrophoresis ◽  
Polyacrylamide Gel ◽  
Molar Ratio ◽  
Rat Serum ◽  
Pregnant Rat ◽  
Isolation And Characterization

A high-affinity riboflavin -binding protein was isolated and characterized for the first time from pregnant-rat sera by affinity chromatography on a lumiflavin-agarose column. The purified protein was homogeneous by the criteria of analytical polyacrylamide-gel disc electrophoresis, gel-filtration chromatography on Sephadex G-100 and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. It had a molecular weight of 90000+/-5000 and interacted with [14C]riboflavin with a 1:1 molar ratio with a dissociation constant (Kd) of 0.42 micron.

Isolation and characterization of the canalicular membrane bile acid transport protein of rat liver

1990 ◽  
Vol 258 (5) ◽  
pp. G728-G737 ◽  
Author(s):  
C. J. Sippel ◽  
M. Ananthanarayanan ◽  
F. J. Suchy
Keyword(s):  
Bile Acid ◽  
Affinity Chromatography ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Disulfonic Acid ◽  
Affinity Column ◽  
Two Dimensional ◽  
Canalicular Membrane ◽  
Isolation And Characterization ◽  
Sds Page

The aim of this study was to isolate the Na(+)-independent bile acid transporter from rat canalicular plasma membranes by affinity chromatography. The affinity matrix used consisted of lysylcholic acid covalently linked to CH-Sepharose 4B, resulting in an anionic ligand essentially identical to glycocholic acid. The protein fraction, adsorbed and eluted from the affinity column, was markedly enriched in a 100-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) compared with the total membrane and membrane extract. The 100-kDa band, further purified by preparative SDS-PAGE, was electroeluted from excised gel fragments and used as an immunogen for antibody production in rabbits. The immune serum, but not preimmune serum, specifically recognized a single, 100-kDa polypeptide on one- and two-dimensional immunoblots of canalicular membranes. In contrast, no reactivity was observed with proteins in liver basolateral or ileal brush-border membranes. The 125I-labeled protein was immunoprecipitated from membrane extracts solubilized in NP-40 and was found to migrate with a pI of 5.3 on two-dimensional electrophoresis. The apparent molecular weight of the protein was reduced by 50% after deglycosylation with N-glycanase. The 100-kDa protein was localized specifically and exclusively by immunocytochemical methods to the bile canalicular domain of the hepatocyte plasma membrane. Moreover, the immunoglobin G fraction prepared from the antiserum significantly inhibited taurocholate transport by canalicular membrane vesicles and decreased the covalent labeling of the 100-kDa protein by the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. Thus the isolation of a single 100-kDa protein by bile acid-affinity chromatography, as well as the inhibitory effects of antibodies directed against this polypeptide, provide further support for its role in the canalicular transport of bile acids.

Pheromaxein, the pheromonal steroid-binding protein, is a major protein synthesized in porcine submaxillary salivary glands

1991 ◽  
Vol 128 (2) ◽  
pp. 205-212 ◽  
Author(s):  
W. D. Booth ◽  
K. I. von Glos
Keyword(s):  
Total Protein ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Submaxillary Gland ◽  
Major Protein ◽  
Sds Page ◽  
Gland Tissue ◽  
Steroid Binding ◽  
Steroid Binding Protein

ABSTRACT Submaxillary salivary gland tissue from large White, Göttingen miniature and Meishan (Chinese) breeds of pig, and European wild boars, was incubated with [35S]methionine. The radiolabelled amino acid was incorporated into protein in all incubations as demonstrated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Specifically [35S]methionine was predominantly incorporated into the α- and β-charge isomers of pheromaxein, a 16-androstene steroid-binding protein, as shown by SDS-PAGE in combination with vertical isoelectric focusing on polyacrylamide slab gels. The synthesis of pheromaxein occurred in submaxillary gland tissue from both sexes, including tissues stored frozen at −70 °C for long periods. There was little evidence for pheromaxein synthesis in parotid gland tissue or skeletal muscle. Total protein, pheromaxein and total 16-androstenes were determined in the submaxillary gland cytosols of six mature Göttingen miniature boars and a positive correlation was found between these glandular constituents. The amounts of endogenous pheromaxein relative to total protein in the submaxillary gland cytosols (range 10·3–18·0%), together with the predominant synthesis of this protein in vitro, indicate that pheromaxein is a major protein produced in porcine submaxillary glands, particularly in those of the male. Journal of Endocrinology (1991) 128, 205–212

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.

scholarly journals Properties of an Fc gamma-binding protein isolated from human leukemic B cells.

1979 ◽  
Vol 150 (5) ◽  
pp. 1049-1066 ◽  
Author(s):  
J Thoenes ◽  
H Stein
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Cell Membranes ◽  
Binding Protein ◽  
Divalent Cations ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sheep Erythrocyte ◽  
Sodium Dodecyl ◽  
Lymphocytic Leukemia ◽  
Prolymphocytic Leukemia ◽  
Gamma Receptor

A selectively Fc gamma-binding protein was isolated from purified and radioiodinated cell membranes from two cases of B-type chronic lymphocytic leukemia and one case of B-type prolymphocytic leukemia by binding to IgG aggregates, horseradish peroxidase-anti-peroxidase IgG complexes, and sheep erythrocyte membrane sheets densely coated with IgG. This protein could not be isolated from the cell membranes of an Fc gamma-receptor-negative chronic lymphocytic leukemia of the T type or from membranes of human erythrocytes. The Fc gamma-binding protein was efficiently solubilized by a mixture of Na-EDTA and 2-mercaptoethanol, but not with one of these agents alone, indicating that both divalent cations and disulfide bridges are involved in the linkage of the Fc gamma-binding protein to the cell membrane. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the Fc gamma-binding protein revealed an apparent mol wt of 28,000 and in isoelectric focusing it showed an isoelectric point of 5.5. The electrophoretic mobility of the 28,000-dalton protein did not change after reduction and alkylation. It was determined that the NH2-terminal amino acid of the protein was glycine. The isolated protein was unable to agglutinate antibody-coated erythrocytes. These findings suggest that the 28,000-dalton IgG-affined protein was composed to O2-enriched buffer lacking reducing agents, the 28,000-dalton protein aggregated to a 115,000-dalton molecule. The isolated Fc gamma-binding protein proved to be different from C1q or its subunits.

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