scholarly journals Purification of a multiprotein complex containing centrosomal proteins from the Drosophila embryo by chromatography with low-affinity polyclonal antibodies.

1992 ◽  
Vol 3 (1) ◽  
pp. 1-11 ◽  
Author(s):  
D R Kellogg ◽  
B M Alberts
Keyword(s):  
Fusion Protein ◽  
Polyclonal Antibodies ◽  
Single Step ◽  
Drosophila Embryo ◽  
Multiprotein Complex ◽  
Immunoaffinity Column ◽  
Centrosomal Protein ◽  
Partial Cdna ◽  
Partial Cdna Clone ◽  
Centrosomal Proteins

A 190-kDa centrosomal protein interacts with microtubules when Drosophila embryo extracts are passed over microtubule-affinity columns. We have obtained a partial cDNA clone that encodes this protein. Using a fusion protein produced from the clone, we have developed a novel immunoaffinity chromatography procedure that allows both the 190-kDa protein and a complex of proteins that associates with it to be isolated in in a single step. For this procedure, the fusion protein is used as an antigen to prepare rabbit polyclonal antibodies, and those antibodies that recognize the 190-kDa protein with low affinity are selectively purified on a column containing immobilized antigen. These low-affinity antibodies are then used to construct an immunoaffinity column. When Drosophila embryo extracts are passed over this column, the 190-kDa protein is quantitatively retained and can be eluted in nearly pure form under nondenaturing conditions with 1.5 M MgCl2, pH 7.6. The immunoaffinity column is washed with 1.0 M KCl just before the elution with 1.5 M MgCl2. This wash elutes 10 major proteins, as well as a number of minor ones. We present evidence that these KCl-eluted proteins represent additional centrosomal components that interact with the 190-kDa protein to form a multiprotein complex within the cell.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

Cloning and characterization of an electrogenic Na/HCO3− cotransporter from the squid giant fiber lobe

2007 ◽  
Vol 292 (6) ◽  
pp. C2032-C2045 ◽  
Author(s):  
Peter M. Piermarini ◽  
Inyeong Choi ◽  
Walter F. Boron
Keyword(s):  
Giant Axon ◽  
Predicted Amino Acid Sequence ◽  
Giant Fiber ◽  
Reading Frame ◽  
Excitable Membranes ◽  
Current Voltage ◽  
Partial Cdna ◽  
Partial Cdna Clone ◽  
Current Voltage Relationship

The squid giant axon is a classic model system for understanding both excitable membranes and ion transport. To date, a Na+-driven Cl-HCO3− exchanger, sqNDCBE—related to the SLC4 superfamily and cloned from giant fiber lobe cDNA—is the only HCO3−-transporting protein cloned and characterized from a squid. The goal of our study was to clone and characterize another SLC4-like cDNA. We used degenerate PCR to obtain a partial cDNA clone (squid fiber clone 3, SF3), which we extended in both the 5′ and 3′ directions to obtain the full-length open-reading frame. The predicted amino-acid sequence of SF3 is similar to sqNDCBE, and a phylogenetic analysis of the membrane domains indicates that SF3 clusters with electroneutral Na+-coupled SLC4 transporters. However, when we measure pHi and membrane potential—or use two-electrode voltage clamping to measure currents—on Xenopus oocytes expressing SF3, the oocytes exhibit the characteristics of an electrogenic Na/HCO3− cotransporter, NBCe. That is, exposure to extracellular CO2/HCO3− not only causes a fall in pHi, followed by a robust recovery, but also causes a rapid hyperpolarization. The current-voltage relationship is also characteristic of an electrogenic NBC. The pHi recovery and current require HCO3− and Na+, and are blocked by DIDS. Furthermore, neither K+ nor Li+ can fully replace Na+ in supporting the pHi recovery. Extracellular Cl− is not necessary for the transporter to operate. Therefore, SF3 is an NBCe, representing the first NBCe characterized from an invertebrate.

The eve stripe 2 enhancer employs multiple modes of transcriptional synergy

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 205-214 ◽  
Author(s):  
D.N. Arnosti ◽  
S. Barolo ◽  
M. Levine ◽  
S. Small
Keyword(s):  
Fusion Protein ◽  
Drosophila Embryo ◽  
Cooperative Binding ◽  
Synergistic Activity ◽  
Detailed Model ◽  
Multiple Modes ◽  
Anterior Half ◽  
Segmentation Process ◽  
Transgenic Embryos ◽  
Cis And Trans

Previous studies have provided a detailed model for the regulation of even-skipped (eve) stripe 2 expression in the Drosophila embryo. The bicoid (bcd) regulatory gradient triggers the expression of hunchback (hb); these work synergistically to activate the stripe in the anterior half of the embryo, bcd also coordinates the expression of two repressors, giant (gt) and Kruppel (Kr), which define the anterior and posterior borders of the stripe, respectively. Here, we report the findings of extensive cis- and trans- complementation analyses using a series of defective stripe 2 enhancers in transgenic embryos. This study reaches two primary conclusions. First, the strip 2 enhancer is inherently ‘sensitized’ for repression by gt. We propose that gt specifies the sharp anterior stripe border by blocking two tiers of transcriptional synergy, cooperative binding to DNA and cooperative contact of bound activators with the transcription complex. Second, we find that the synergistic activity of hb and bcd is ‘promiscuous’. For example, a maternally expressed Gal4-Sp1 fusion protein can functionally replace hb in the stripe 2 enhancer. This finding challenges previous proposals for dedicated hb and bcd interactions in the segmentation process.

scholarly journals Identification of Rab6 as an N-ethylmaleimide-sensitive fusion protein-binding protein

2000 ◽  
Vol 352 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Sang Yeul HAN ◽  
Dong Yoon PARK ◽  
Sang Dai PARK ◽  
Seung Hwan HONG
Keyword(s):  
Fusion Protein ◽  
Atpase Activity ◽  
Atp Hydrolysis ◽  
Polyclonal Antibodies ◽  
Binding Protein ◽  
Vesicular Transport ◽  
Brain Extract ◽  
Terminal Domain ◽  
Protein Receptor ◽  
And Function

In this study we show the interaction of N-ethylmaleimide-sensitive fusion protein (NSF) with a small GTP-binding protein, Rab6. NSF is an ATPase involved in the vesicular transport within eukaryotic cells. Using the yeast two-hybrid system, we have isolated new NSF-binding proteins from the rat lung cDNA library. One of them was Rab6, which is involved in the vesicular transport within the Golgi and trans-Golgi network as a Ras-like GTPase. We demonstrated that the N-terminal domain of NSF interacted with the C-terminal domain of Rab6, and these proteins were co-immunoprecipitated from the rat brain extract. This interaction was maintained preferentially in the presence of hydrolysable ATP. Recombinant NSF-His6 can also bind to C-terminal Rab6–glutathione S-transferase under the conditions to allow the ATP hydrolysis. Surprisingly, Rab6 stimulates the ATPase activity of NSF by approx. 2-fold as does α-soluble NSF attachment protein receptor. Anti-Rab6 polyclonal antibodies significantly inhibited the Rab6-stimulated ATPase activity of NSF. Furthermore, we found that Rab3 and Rab4 can also associate with NSF and stimulate its ATPase activity. Taken together, we propose a model in which Rab can form an ATP hydrolysis-regulated complex with NSF, and function as a signalling molecule to deliver the signal of vesicle fusion through the interaction with NSF.

scholarly journals Analysis of the Respiratory Syncytial Virus Fusion Protein Using Monoclonal and Polyclonal Antibodies

1986 ◽  
Vol 67 (3) ◽  
pp. 505-513 ◽  
Author(s):  
E. E. Walsh ◽  
P. J. Cote ◽  
B. F. Fernie ◽  
J. J. Schlesinger ◽  
M. W. Brandriss
Keyword(s):  
Respiratory Syncytial Virus ◽  
Fusion Protein ◽  
Polyclonal Antibodies ◽  
Virus Fusion ◽  
Syncytial Virus

Isolation of a cDNA clone complementary to sequences for a 34-kilodalton protein which is a pp60v-src substrate

1984 ◽  
Vol 4 (9) ◽  
pp. 1935-1938
Author(s):  
H G Tomasiewicz ◽  
R Cook-Deegan ◽  
D M Chikaraishi
Keyword(s):  
Cdna Clone ◽  
Chicken Embryo ◽  
Kinase Activity ◽  
Chicken Embryo Fibroblast ◽  
Src Kinase ◽  
Cell Protein ◽  
Fibroblast Cells ◽  
Chicken Cell ◽  
Partial Cdna ◽  
Partial Cdna Clone

We have isolated a partial cDNA clone containing sequences complementary to a mRNA encoding a 34- to 36-kilodalton normal chicken cell protein which is a substrate for pp60v-src kinase activity. Using this 34-kilodalton cDNA clone as a probe, we determined that the size of the 34-kilodalton mRNA was 1,100 nucleotides and the level of the 34-kilodalton RNA was the same in various tissues of mature chickens but was significantly higher in chicken embryo fibroblast cells.

Characterization of the rabbit renal Na(+)-dicarboxylate cotransporter using antifusion protein antibodies

1996 ◽  
Vol 271 (6) ◽  
pp. C1808-C1816 ◽  
Author(s):  
A. M. Pajor ◽  
N. Sun
Keyword(s):  
Fusion Protein ◽  
Brush Border ◽  
Xenopus Oocytes ◽  
Polyclonal Antibodies ◽  
Membrane Vesicles ◽  
Site Directed Mutagenesis ◽  
In Vitro Translation ◽  
Western Blots ◽  
Renal Brush Border Membrane

Polyclonal antibodies were prepared against the rabbit renal Na(+)-dicarboxylate cotransporter, NaDC-1. The antibodies were raised in chickens against a fusion protein consisting of a 60-amino acid peptide from NaDC-1 and glutathione S-transferase. These antibodies specifically recognized the fusion protein in Western blots and could immunoprecipitate the full-length NaDC-1 after in vitro translation. The antifusion protein antibodies specifically recognized a protein of 63 kDa in rabbit renal brush-border membrane vesicles (BBMV), similar to the predicted mass of 66 kDa. Two proteins of 57 and 115 kDa were recognized in rabbit intestinal brush-border membranes. A protein of 66 kDa was recognized in Xenopus oocytes injected with NaDC-1 cRNA. Enzymatic deglycosylation of rabbit renal BBMV resulted in a decrease in mass by 11 kDa, consistent with N-glycosylation at a single site. Site-directed mutagenesis of the two consensus sequences for N-glycosylation in the NaDC-1 cDNA showed that Asn-576, located near the COOH-terminal, is glycosylated. The nonglycosylated mutant of NaDC-1 exhibited 50% of wild-type succinate transport activity when expressed in Xenopus oocytes, suggesting that glycosylation is not essential for function. The revised secondary structure model of NaDC-1 contains 11 putative transmembrane domains and an extracellular glycosylated COOH-terminal.

MOLECULAR CLONING OF PLATELET GPIIb FROM HEL CELLS AND HUMAN MEGAKARYOCYTES

1987 ◽  
Author(s):  
G Uzan ◽  
A Lajmanovich ◽  
M H Prandini ◽  
Ph Frachet ◽  
A Duperray ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Fusion Protein ◽  
Recombinant Dna ◽  
Polyclonal Antibodies ◽  
Northern Blotting ◽  
Cellular Systems ◽  
Hel Cells ◽  
Function Relationship ◽  
Von Willebrand ◽  
Relationship Of

Platelet GP IIb-IIIa is an heterodimer which functions as a receptor for fibrinogen, fibronectin and Von Willebrand factor and is implicated in platelet adhesive reactions. To study the structure function relationship of this glycoprotein, a recombinant DNA approach was initiated. cDNA expression libraries were constructed in » gtll vector, from erythro-leukemia cells (HEL) and megakaryocytes mRNA. The human megakaryocytes were isolated from patients with chronic myeloid leukemia. The HEL library was initially screened with polyclonal antibodies anti GPIIb IIIa. One clone, λIIbI, containing a 1.65 kbp insert reacted with a panel of different polyclonal antibodies anti GPIIb IIIa and a monoclonal antibody anti GPIIb. To further characterize this clone the synthesis of the fusion protein was induced by IPTG. The bacterial protein was then blotted onto nitro cellulose and incubated with antisera anti GPIIb-IIIa. Antibodies that specifically bound with the fusion protein were eluted and tested on platelet membrane extracts. The selected antibodies produced a positive signal at the GPIIb position similar to the signal produced by the monoclonal antibody anti GPIIb on the same membrane extract. Finally on western blotting, a protein of Mr= 170kD reacted with the monoclonal antibody anti GPIIb. λIIbI insert was used to screen the megakaryocyte library and 3 clones, λIIb2,λIIb3 and λIIb4 were isolated. The size of HEL cells and megakaryocytes GPIIb mRNA was estimated by northern blotting. Only one species of 3.9 kb was identified in both cells. The four different clones accounted for 50% of the coding sequence of this mRNA.Sequencing of these cDNAs indicated that the plasmatic domain of GPIIb contains a cystein rich region. The sequence of these clones will allow the study of the adhesines genetic diversity in different cellular systems.

Cortisol alters carbonic anhydrase-mediated renal sulfate secretion

2003 ◽  
Vol 285 (6) ◽  
pp. R1430-R1438 ◽  
Author(s):  
Ryan M. Pelis ◽  
James E. Goldmeyer ◽  
Joseph Crivello ◽  
J. Larry Renfro
Keyword(s):  
Carbonic Anhydrase ◽  
Proximal Tubule ◽  
Plasma Membranes ◽  
Sequence Similarity ◽  
Renal Proximal Tubule ◽  
Protein Abundance ◽  
High Sequence Similarity ◽  
Partial Cdna ◽  
Partial Cdna Clone ◽  
Low Cortisol

Active transepithelial sulfate secretion rate by winter flounder renal proximal tubule epithelium in primary culture (fPTC) is dependent on intracellular carbonic anhydrase (CA) and enhanced by cortisol. To further evaluate this relationship, a partial cDNA clone (327 bp) of carbonic anhydrase II (CAII) with high sequence similarity to CAII from numerous species including fish, chicken, and human was obtained from fPTCs. The majority of CA activity and CAII protein was present in the cytosol of fPTCs; however, significant amounts of both (in addition to SDS-resistant CA activity, i.e., CAIV-like isoform) were present in concentrated plasma membranes. CAII from concentrated membranes migrated differently than purified CAII on nondenaturing PAGE gels, suggesting that CAII associates with another membrane component. Treatment of fPTCs with the cell-soluble CA inhibitor methazolamide (100 μM) caused a 58% reduction in active transepithelial SO42- secretion. fPTCs that were previously cultured under high-cortisol concentrations, when subjected to 5 days of low physiological levels of cortisol, had decreased CA activity (28%), CAII protein abundance (65%), and net active SO42- secretion (28%), with no effect on epithelial differentiation. Methazolamide and low-cortisol treatment in combination inhibited net active SO42- secretion 56%, which was not different than the effect of methazolamide treatment alone. These data indicate that cortisol directly increases renal CA activity, CAII protein abundance, and CA-dependent SO42- secretion in the marine teleost renal proximal tubule.

Sign in / Sign up

Export Citation Format

Share Document