Eimeria tenella sporozoites: the method of excystation affects the surface membrane proteins

Parasitology ◽  
1987 ◽  
Vol 95 (3) ◽  
pp. 479-489 ◽  
Author(s):  
M. H. Wisher ◽  
M. E. Rose

SUMMARYEimerian sporozoites can be recovered from intestinal washings after oral administration of oocysts to chickens but suspensions of sporozoites are usually prepared in the laboratory by incubation of sporocysts or fractured oocysts in vitro, at body temperatures, with relatively high concentrations of trypsin and bile salts. Since these agents affect membrane structure, the surface membrane of proteins of Eimeria tenella sporozoites excysted in vivo and in vitro have been compared. Surface radio-iodination followed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) showed that more 125I was incorporated into polypeptides on sporozoites excysted in vivo than on sporozoites excysted in vitro. The 125I-polypeptide profile of sporozoites excysted in vivo was more resistant to subsequent incubation with pure trypsin than that of sporozoites excysted in vitro, but incubation with bile salts resulted in the loss of some iodinated polypeptides from both preparations of iodinated sporozoites. Reaction with combinations of crude trypsin and bile salts led to the lysis of sporozoites. The method of excystation had no effect on the reaction of convalescent chicken serum with Western blots of sporozoites but the results of immunofluorescent staining carried out with mouse monoclonal antibodies indicated that the structure of the cell surface was altered and some antigenic determinants were lost from sporozoites excysted in vitro. In contrast, neither the infectivity of sporozoites determined in vivo, nor their invasion of cultured cells was changed by the method of excystation.

1982 ◽  
Vol 156 (5) ◽  
pp. 1312-1324 ◽  
Author(s):  
A G Barbour ◽  
S L Tessier ◽  
H G Stoenner

Borrelia hermsii, a relapsing fever agent, manifests antigenic variation in vivo and in vitro. We studied three mouse-passaged serotypes of strain HS1 (7, 14, and 21) and a HS1 derivative obtained after multiple in vitro passages (C serotype). All four serotypes had two major proteins in whole cell lysates fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One major protein species (pII) had the same apparent subunit molecular weight (or approximately 3.9 X 10(4) in all the serotypes. In contrast, the other abundant protein in lysates, pI, had a different apparent molecular weight in each serotype. In one gel the molecular weights of pIc, pI7, pI14, and pI21 were 1.9, 4.2, 4.1, and 4.0 X 10(4), respectively. Serotype-specific mouse antisera bound to both hemologous and heterologous pIIs, to homologous pI, but not to heterologous pI in Western blots. Hybridomas were raised from spleens of mice infected with B. hermsii. Monoclonal antibodies were identified by immunofluorescence assays using whole organisms. Monoclonal antibodies specific for serotype 7 (H1826) or for serotype 21 (H3326) bound only to pI7 or pI21, respectively, in Western blots. The surface location of the pI was suggested not only by the immunofluorescence studies but also by the labeling of pI7 and pI21 when whole cells of serotypes 7 and 21 were incubated with 125I in the presence of Iodogen. Under the same circumstances, pII was relatively poorly labeled. These studies have identified the variable pI proteins of B. hermsii as serotype-specific antigens. A change from one pI to another may be the basis of antigenic variation of Borrelia species during relapsing fever.


1998 ◽  
Vol 66 (9) ◽  
pp. 4374-4381 ◽  
Author(s):  
John C. McMichael ◽  
Michael J. Fiske ◽  
Ross A. Fredenburg ◽  
Deb N. Chakravarti ◽  
Karl R. VanDerMeid ◽  
...  

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.


1983 ◽  
Vol 59 (1) ◽  
pp. 81-103 ◽  
Author(s):  
R. Crossley ◽  
D.V. Holberton

Proteins from the axonemes and disc cytoskeleton of Giardia lamblia have been examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. In addition to tubulin and the 30 X 10(3) molecular weight disc protein, at least 18 minor components copurify with the two major proteins in Triton-insoluble structures. The most prominent minor bands have the apparent molecular weights of 110 X 10(3), 95 X 10(3) and 81 X 10(3). Protein of 30 X 10(3) molecular weight accounts for about 20% of organelle protein on gels. In continuous 25 mM-Tris-glycine buffer it migrates mostly as a close-spaced doublet of polypeptides, which are here given the name giardins. Giardia tubulin and giardin have been purified by gel filtration chromatography in the presence of sodium dodecyl sulphate. Well-separated fractions were obtained that could be further characterized. Both proteins are heterogeneous when examined by isoelectric focusing. Five tubulin chains were detected by PAGE Blue 83 dye-binding after focusing in a broad-range ampholyte gel. Giardin is slightly less acidic than tubulin. On gels it splits into four major and four minor chains with isoelectric points in the pI range from 5.8 to 6.2. The amino acid composition of the giardin fraction has been determined, and compared to Giardia tubulin and a rat brain tubulin standard. Giardins are rich in helix-forming residues, particularly leucine. They have a low content of proline and glycine; therefore they may have extensive alpha-helical regions and be rod-shaped. As integral proteins of disc microribbons, giardins in vivo associate closely with tubulin. The properties of giardins indicate that in a number of respects - molecular size, charge, stoichiometry - their structural interaction with tubulin assemblies will be different from other tubulin-accessory protein copolymers studied in vitro.


Author(s):  
M Karunakaran ◽  
Vivek C Gajare ◽  
Ajoy Mandal ◽  
Mohan Mondal ◽  
S K Das ◽  
...  

This experiment was conducted to study the electrophoretic characters of heparin binding proteins (HBP) of Black Bengal buck semen and their correlation with sperm characters and cryo-survivability. Semen ejaculates (n=20/buck) were collected from nine bucks and in vitro sperm characters were evaluated at collection, after equilibration and after freeze - thawing. HBP were isolated through heparin column and discontinuous Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) was performed to assess molecular weight. Significant difference (plessthan0.01) were observed among the bucks in sperm characters and freezability. Eight protein bands of 17 to 180 kDa in seminal plasma and 7 bands in sperm were found. 180 -136 kDa HBP of seminal plasma and 134-101 kDa HBP of sperm had showed high correlation with in vitro sperm characters. Further studies on identification of these proteins and their correlation with in vivo pregnancy are needed to find their role as marker for buck selection.


2000 ◽  
Vol 78 (3) ◽  
pp. 328-335 ◽  
Author(s):  
Christine Masterson ◽  
Clifford Wood

Carnitine palmitoyltransferase (EC 2.3.1.21), an enzyme that catalyses the reversible transfer of activated long-chain acyl groups between CoASH and L-carnitine, has been confirmed in pea leaf chloroplasts. This enzyme is bound to the chloroplast inner envelope membrane and has two isoforms, one bound to the outside (cytosol side) of the inner envelope and one bound to the inside (stromal side) of the inner envelope. Malonyl CoA inhibited the activity of the outer carnitine palmitoyltransferase, while stimulating the activity of the inner isoform and may be a regulator of these enzymes in vivo. Carnitine palmitoyltransferase was solubilized from the chloroplast envelope by detergent treatment and the two isoforms separated by Q-Sepharose anion exchange chromatography. Both proteins were immunochemically observed by probing Western blots of sodium dodecyl sulfate - polyacrylamide gel electrophoresis gels using an anti-beef heart mitochondrial carnitine palmitoyltransferase polyclonal antibody. The monomeric molecular mass of the protein recognized by this antibody was approximately 20 kDa. This 20-kDa protein also bound3H-carnitine. Both isoforms had broad acyl CoA substrate specificities, but showed increased activity with desaturated long-chain acyl CoAs, exhibiting a preference for linolenoyl CoA. A role for carnitine palmitoyltransferase in the shuttling of fatty acids across the chloroplast envelope is suggested.Key words: Pisum sativum, chloroplasts, carnitine palmitoyltransferase, fatty acid metabolism, eukaryotic pathway, membrane transport.


Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2283-2290 ◽  
Author(s):  
H Hoogendoorn ◽  
CH Toh ◽  
ME Nesheim ◽  
AR Giles

In previous studies using a nonhuman primate model of Protein C (PC) activation in vivo, immunoblotting showed substantial amounts of activated PC (APC) in a high molecular weight complex with what was presumed to be a previously unrecognized APC binding protein. This APC complex can also be formed in citrated plasma in vitro. It is of low electrophoretic mobility, sodium dodecyl sulfate (SDS) stable, with an apparent Mr of 320 Kd. Its purification from human plasma was accomplished using barium citrate adsorption, sequential polyethylene glycol (PEG) precipitations, diethylaminoethyl sepharose chromatography, AcA-34 gel filtration, and zinc-chelate affinity chromatography. This was monitored by subjecting the fractions to nondenaturing polyacrylamide gel electrophoresis (PAGE), transfer to polyvinylidene-difluoride membranes, and probing with 125I-labeled human APC. The purified APC-binding protein was homogeneous by SDS-PAGE with an Mr of 275 Kd. Its identity as alpha 2-macroglobulin (alpha 2M) was demonstrated immunochemically. Complex formation between alpha 2M and APC was found to be almost completely inhibited by EDTA, but to a lesser extent by citrate. Complex formation could also be prevented by active site inhibition with D-Phenylalanyl-L-Prolyl-L-Arginine- Chloromethyl Ketone (PPACK) or pretreatment of alpha 2M with methylamine. Incubation of APC (33 nmol/L) with alpha 2M (1 mumol/L) resulted in time-dependent inhibition of APC anticoagulant activity when measured using an activated partial thromboplastin time based APC assay. These data show that alpha 2M binds and inhibits APC in vitro and the interaction is both metal-ion and active-site dependent, requiring functionally intact alpha 2M. As the complexes formed in vitro comigrate electrophoretically with those observed in vivo after PC activation, it is suggested that alpha 2M is a physiologically relevant inhibitor involved in the processing of APC in vivo.


1998 ◽  
Vol 72 (4) ◽  
pp. 3029-3036 ◽  
Author(s):  
S. X. Wu ◽  
X. P. Zhu ◽  
G. J. Letchworth

ABSTRACT Nine glycoproteins (gB, gC, gD, gE, gG, gH, gI, gK, and gL) have been identified in bovine herpesvirus 1 (BHV-1). gM has been identified in many other alpha-, beta-, and gammaherpesviruses, in which it appears to play a role in membrane penetration and cell-to-cell fusion. We sought to express BHV-1 open reading frame UL10, which encodes gM, and specifically identify the glycoprotein. We corrected a frameshift error in the published sequence and used the corrected sequence to design coterminal peptides from the C terminus. These were expressed as glutathione S-transferase fusion proteins inEscherichia coli. The fusion protein containing the 63 C-terminal amino acids from the corrected gM sequence engendered antibodies that immunoprecipitated a 30-kDa protein from in vitro translation reactions programmed with the UL10 gene. Proteins immunoprecipitated by this antibody from virus-infected cells ran at 36 and 43 kDa in reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and 43 and 48 kDa in nonreducing SDS-PAGE. Only the larger of the pair was present in virions. A 7-kDa protein was released from gM by reducing agents. The 7-kDa protein was not recognized in Western blots probed with the anti-gM antibody but reacted specifically with antibodies prepared against BHV-1 UL49.5, previously reported to be a 9-kDa protein associated with an unidentified 39-kDa protein (X. Liang, B. Chow, C. Raggo, and L. A. Babiuk, J. Virol. 70:1448–1454, 1996). This is the first report of a small protein covalently bound to any herpesvirus gM. Similar patterns of hydrophobic domains and cysteines in all known gM and UL49.5 homologs suggest that these two proteins may be linked by disulfide bonds in all herpesviruses.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ping Xiao ◽  
Hongzhi Huang ◽  
Xiang Li ◽  
Jianwei Chen ◽  
Jin-ao Duan

Abstract Background Radix isatidis (Isatis indigotica Fort.) is an ancient medicinal herb, which has been applied to the prevention and treatment of influenza virus since ancient times. In recent years, the antioxidant activity of Radix isatidis has been widely concerned by researchers. Our previous studies have shown that Radix isatidis protein (RIP) has good antioxidant activity in vitro. In this study, the composition of the protein was characterized and its antioxidant activity in vivo was evaluated. Methods The model of oxidative damage in mice was established by subcutaneous injection of D-galactose for 7 weeks. Commercially available kits were used to determine the content of protein and several oxidation indexes in different tissues of mice. The tissue samples were stained with hematoxylin and eosin (H&E) and the pathological changes were observed by optical microscope. The molecular weight of RIP was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The amino acid composition of RIP was determined by a non-derivative method developed by our research group. Results RIP significantly increased the activities of antioxidant enzymes such as SOD, CAT, GSH-Px and total antioxidant capability (TAOC) but decreased the MDA level in the serum, kidney and liver. H&E stained sections of liver and kidney revealed D-galactose could cause serious injury and RIP could substantially attenuate the injury. The analysis of SDS-PAGE showed that four bands with molecular weights of 19.2 kDa, 21.5 kDa, 24.8 kDa and 40.0 kDa were the main protein components of RIP. Conclusions The results suggested that RIP had excellent antioxidant activity, which could be explored as a health-care product to retard aging and a good source of protein nutrition for human consumption.


1993 ◽  
Vol 265 (2) ◽  
pp. G231-G241 ◽  
Author(s):  
J. M. Crothers ◽  
D. C. Chow ◽  
J. G. Forte

Amounts and fractional distributions of gastric H(+)-K(+)-adenosinetriphosphatase (ATPase) activity and H(+)-K(+)-ATPase protein as well as properties of H(+)-K(+)-ATPase-containing membranes were studied in rabbits injected with omeprazole (OM; 1 mg/kg sc twice daily for 5 days). Total H(+)-K(+)-ATPase activity decreased to 22 +/- 2% of control (n = 4). Densitometry of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blots showed H(+)-K(+)-ATPase protein was decreased to 60-70% of control. In vitro reduction of the enzyme-OM disulfide bond with 0.1 M 2-mercaptoethanol increased microsomal H(+)-K(+)-ATPase activity to 56 +/- 7% of control (n = 3), consistent with a substantial decrease in enzyme protein. Incorporation of 35S-labeled methionine for 30 min before death resulted in 2.2-fold more label per unit of microsomal alpha-subunit protein (5 days OM vs. control). Thus the decrease in enzyme protein resulted from increased breakdown rather than decreased synthesis. A striking shift in distribution of H(+)-K(+)-ATPase-containing microsomes (tubulovesicles) on sucrose gradients reflected slow equilibration of most control vesicles with the gradient medium and faster equilibration after 5 days OM, indicating increased permeability. After 5 days OM, microsomal vesicle acidification (by acridine orange uptake assay) was negligible, even with 2-mercaptoethanol treatment, and H+ leakage on sudden delta pH was faster than control. We conclude that extended OM treatment not only inhibits H(+)-K(+)-ATPase but accelerates its breakdown and renders H(+)-K(+)-ATPase-containing membranes more permeable. It is thus possible that increased backward H+ flux contributes to profound inhibition of acid secretion during extended omeprazole treatment. In parallel experiments, H(+)-K(+)-ATPase activity and density gradient sedimentation of tubulovesicles returned to near normal 3 days after OM withdrawal.


Author(s):  
Doris Palmer Booth

The role of pili as a mucosal attachment factor that enhances colonization and pathogenicity is well known in Escherichia coli, Neisseria gonorrhea, Streptococcus pyrogenes and Proteus mirabilis. Although Haemophilus influenzae type b (Hib) causes serious infections in children such as meningitis, pneumonia, septic arthritis and epiglottitis, very little information is available about Hib piliation and subsequent adhesion and colonization in vivo. Hib piliation was recently correlated with hemagglutination and adherence (in vitro) to human buccal epithelial cells by Pichichero, et al.Pili are protein structures which extend from the outer membrane of Hib. Purified pili have an apparent molecular weight of 23,000 daltons by Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and aggregate laterally as well as end on end to form thick filamentous structures. Although pili seem to enhance attachment to respiratory mucosa (a significant foothold during the invasion of healthy tissue) the relative pathogenicity of piliated and non-piliated Hib is yet to be determined.


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