scholarly journals Degradation of proteins in rat liver mitochondrial outer membrane transplanted into different cell types. Evidence for alternative processing

1984 ◽  
Vol 220 (2) ◽  
pp. 489-498 ◽  
Author(s):  
S M Russell ◽  
J S Amenta ◽  
R J Mayer
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Average Rate ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
A549 Cells ◽  
Rat Hepatocytes ◽  
Mitochondrial Outer Membrane ◽  
Plasma Membrane Proteins

The degradation of proteins in reductively [3H]methylated mitochondrial outer membrane (MOM) transplanted into cells by a poly(ethylene glycol)-mediated process has been studied. The average rate of degradation (t1/2 24-28 h) of MOM proteins transplanted into HTC cells was not the same as for endogenous MOM proteins (t1/2 56 h), mitoplast proteins (t1/2 120 h), plasma membrane proteins (t1/2 approx. 90 h) or cytosol proteins (t1/2 75 h). The degradation of transplanted MOM proteins was inhibited to the same extent (30-45%) as that of endogenous mitochondrial and plasma membrane proteins by leupeptin and NH4Cl. No inhibition of HTC cell cytosol protein degradation by NH4Cl was observed. NH4Cl differentially inhibited the degradation of endogenous MOM and mitoplast protein subunits as shown after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Proteins in MOM transplanted into tissue culture cells were degraded either with t1/2 24-28 h (MRC-5, B82 and A549 cells) or with t1/2 55-70 h (CHO-K1 and 3T3-L1 cells) similar to that of proteins in MOM transplanted into rat hepatocytes [Evans & Mayer (1983) Biochem. J. 216, 151-161]. The data suggest that membrane protein destruction is but the end part of a fundamental intracellular membrane recognition process.

scholarly journals Purification of a protein having pore forming activity from the rat liver mitochondrial outer membrane

1982 ◽  
Vol 208 (1) ◽  
pp. 77-82 ◽  
Author(s):  
M Lindén ◽  
P Gellerfors ◽  
B D Nelson
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Rat Liver ◽  
Gradient Centrifugation ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Mitochondrial Outer Membrane ◽  
Rat Liver Mitochondria ◽  
Charge Heterogeneity

A protein with pore-forming activity has been isolated from the outer membrane of rat liver mitochondria. The purification involves sucrose gradient centrifugation, differential centrifugation in the presence of Triton X-100, and DEAE-Sepharose and CM-Sepharose chromatography. The yield of the purified protein was approx. 2% of the total outer membrane proteins. The protein, when inserted into soya bean phospholipid vesicles, increases the [3H]sucrose permeability of the vesicles but had no effect on the permeability of high-molecular-weight [14C]dextran (Mr 70 000). The protein is very active, since as little as 3-4 micrograms of protein per mg of phospholipid is required for the complete release of [3H]sucrose from the vesicles. Sucrose diffusion channels could not be reconstituted with other membrane proteins such as rat liver cytochrome oxidase or cytochrome b5. Purified pore protein revealed a single band of apparent Mr 30000 when resolved by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This polypeptide could be further resolved by isoelectric focusing into a major (pI7.9) and two relatively minor (pI7.6 and 7.2) components. Proteolytic mapping with V8 proteinase from Staphylococcus aureus suggests that these probably represent a single component showing charge heterogeneity. The reason for the charge heterogeneity is not known. The amino acid composition of the protein revealed 47.8% polar amino acids with a relatively high lysine content.

scholarly journals Identification of Polymorphic Outer Membrane Proteins of Chlamydia psittaci 6BC

2001 ◽  
Vol 69 (4) ◽  
pp. 2428-2434 ◽  
Author(s):  
Regina J. Tanzer ◽  
David Longbottom ◽  
Thomas P. Hatch
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Disulfide Bonds ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Late Phase ◽  
Sodium Dodecyl ◽  
Chlamydia Psittaci ◽  
Developmental Cycle ◽  
Lauryl Sarcosine

ABSTRACT The genomes of Chlamydia spp. encode a family of putative outer membrane proteins, referred to as polymorphic outer membrane proteins (POMPs), which may play a role in the avoidance of host immune defenses. We analyzed avian strain 6BC of Chlamydia psittaci by polyacrylamide gel electrophoresis for the expression of POMPs. At least six putative POMPs were identified on the basis of their size (90 to 110 kDa) and labeling with an outer membrane-specific probe, 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine. Three of the putative POMPs reacted with antiserum raised against a recombinant ovine C. psittaci strain POMP, and two possessed surface-exposed, trypsin-sensitive sites. The POMPs were dependent on disulfide bonds for their maintenance in sodium lauryl sarcosine- and sodium dodecyl sulfate-insoluble complexes but did not appear to be interpeptide disulfide bond cross-linked. The putative POMPs were found to be synthesized during the late phase of the chlamydial developmental cycle, cotemporally with the cysteine-rich doublet periplasmic proteins.

Outer membrane proteins from Serratia marcescens

1993 ◽  
Vol 39 (1) ◽  
pp. 108-111 ◽  
Author(s):  
Marta Puig ◽  
Carme Fusté ◽  
Miquel Viñas
Keyword(s):  
Membrane Proteins ◽  
Serratia Marcescens ◽  
Outer Membrane ◽  
Nutrient Availability ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cultural Conditions

The outer membrane proteins (OMPs) of several strains of Serratia marcescens have been studied by sodium dodecyl sulphate – urea – polyacrylamide gel electrophoresis. Four major OMPs, named Omp1, Omp2, Omp3, and OmpA (42, 40, 39, and 37 kDa, respectively), have been visualized. The relative proportions of Omp2 and Omp3 depend on cultural conditions (temperature of incubation, osmolarity, and nutrient availability).Key words: Serratia marcescens, outer membrane proteins, porin.

scholarly journals Establishing a Direct Role for the Bartonella bacilliformis Invasion-Associated Locus B (IalB) Protein in Human Erythrocyte Parasitism

2001 ◽  
Vol 69 (7) ◽  
pp. 4373-4381 ◽  
Author(s):  
Sherry A. Coleman ◽  
Michael F. Minnick
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Protein Localization ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Buoyant Density ◽  
Sodium Dodecyl ◽  
Amino Acid Sequence Similarity ◽  
Bartonella Bacilliformis ◽  
Sds Page

ABSTRACT The invasion-associated locus A and B genes (ialAB) ofBartonella bacilliformis were previously shown to confer an erythrocyte-invasive phenotype upon Escherichia coli, indirectly implicating their role in virulence. We report the first direct demonstration of a role for ialB as a virulence factor in B. bacilliformis. The presence of a secretory signal sequence and amino acid sequence similarity to two known outer membrane proteins involved in virulence suggested that IalB was an outer membrane protein. To develop an antiserum for protein localization, the ialB gene was cloned in frame into an expression vector with a six-histidine tag and under control of thelacZ promoter. The IalB fusion protein was purified by nickel affinity chromatography and used to raise polyclonal antibodies. IalB was initially localized to the bacterial membrane fraction. To further localize IalB, B. bacilliformis inner and outer membranes were fractionated by sucrose density gradient centrifugation and identified by appearance, buoyant density (ρ), and cytochromeb content. Inner and outer membrane proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and IalB was positively identified by Western blot. Contrary to expectations, IalB was localized to the inner membrane of the pathogen. To directly demonstrate a role for IalB in erythrocyte parasitism, the B. bacilliformis ialB gene was disrupted by insertional mutagenesis. The resulting ialB mutant strain was complemented in trans with a replicative plasmid encoding the full-length ialB gene. PCR and high-stringency DNA hybridization confirmed mutagenesis and transcomplementation events. Abrogation and restoration of ialB expression was verified by SDS-PAGE and immunoblotting. In vitro virulence assays showed that mutagenesis of ialB decreased bacterial association and invasion of human erythrocytes by 47 to 53% relative to controls. Transcomplementation of ialB restored erythrocyte association and invasion rates to levels observed in the parental strain. These data provide direct evidence for IalB's role in erythrocyte parasitism and represent the first demonstration of molecular Koch's postulates for a Bartonella species.

Myogenesis of normal and dystrophic chick embryonic skeletal muscle cells in vitro: biosynthesis of plasma membrane proteins

1980 ◽  
Vol 58 (10) ◽  
pp. 1156-1164 ◽  
Author(s):  
Paul C. Holland ◽  
George A. Cates ◽  
Byron S. Wenger ◽  
Barbara L. Raney
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Plasma Membranes ◽  
Protein Biosynthesis ◽  
Sodium Dodecyl ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Plasma Membrane Proteins ◽  
Dystrophic Muscle

Plasma membranes were prepared from primary cell cultures of normal and genetically dystrophic chick embryonic pectoral muscle. These membranes were analyzed both by one-dimensional sodium dodecyl sulphate – polyacrylamide slab gel electrophoresis and by two-dimensional electrophoresis using isoelectric focusing in the first dimension. No marked and reproducible abnormalities could be detected in the synthesis, or accumulation, of plasma membrane proteins of dystrophic muscle cells maintained in culture for periods of up to 6 days. Analysis of the relative rates of protein turnover, analysis of fucose incorporation into plasma membrane proteins, and comparison of iodinated cell surface proteins also failed to reveal distinct abnormalities in plasma membranes derived from cultured dystrophic muscle cells. Although the results obtained do not rule out an early defect in plasma membrane protein biosynthesis during the development of dystrophic skeletal muscle in vivo, they do demonstrate that the synthesis and assembly of at least the major plasma membrane proteins occur normally during the initial phases of terminal differentiation of isolated dystrophic skeletal muscle cells in tissue culture.

scholarly journals Isolation and Characterization of Vibrio tubiashii Outer Membrane Proteins and Determination of a toxR Homolog

2007 ◽  
Vol 74 (3) ◽  
pp. 907-911 ◽  
Author(s):  
J. Jean-Gilles Beaubrun ◽  
M. H. Kothary ◽  
S. K. Curtis ◽  
N. C. Flores ◽  
B. E. Eribo ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Growth Conditions ◽  
Isolation And Characterization ◽  
Vibrio Tubiashii

ABSTRACT Outer membrane proteins (OMPs) expressed by Vibrio tubiashii under different environmental growth conditions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and PCR analyses. Results showed the presence of a 38- to 40-kDa OmpU-like protein and ompU gene, a maltoporin-like protein, several novel OMPs, and a regulatory toxR homolog.

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