scholarly journals The epididymal soluble prion protein forms a high-molecular-mass complex in association with hydrophobic proteins

2005 ◽  
Vol 392 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Heath Ecroyd ◽  
Maya Belghazi ◽  
Jean-Louis Dacheux ◽  
Jean-Luc Gatti
Keyword(s):  
Molecular Mass ◽  
Prion Protein ◽  
Hydrophobic Interactions ◽  
Protein Complexes ◽  
Biochemical Properties ◽  
High Molecular Mass ◽  
Soluble Form ◽  
Disulphide Bonds ◽  
Apolipoprotein J ◽  
Associated Proteins

We have shown previously that a ‘soluble’ form of PrP (prion protein), not associated with membranous vesicles, exists in the male reproductive fluid [Ecroyd, Sarradin, Dacheux and Gatti (2004) Biol. Reprod. 71, 993–1001]. Attempts to purify this ‘soluble’ PrP indicated that it behaves like a high-molecular-mass complex of more than 350 kDa and always co-purified with the same set of proteins. The main associated proteins were sequenced by MS and were found to match to clusterin (apolipoprotein J), BPI (bacterial permeability-increasing protein), carboxylesterase-like urinary excreted protein (cauxin), β-mannosidase and β-galactosidase. Immunoblotting and enzymatic assay confirmed the presence of clusterin and a cauxin-like protein and showed that a 17 kDa hydrophobic epididymal protein was also associated with this complex. These associated proteins were not separated by a high ionic strength treatment but were by 2-mercaptoethanol, probably due to its action on reducing disulphide bonds that maintain the interaction of components of the complex. Our results suggest that the associated PrP retains its GPI (glycosylphosphatidylinositol) anchor, in contrast with brain-derived PrP, and that it is resistant to cleavage by phosphatidylinositol-specific phospholipase C. Based on these results, the identity of the associated proteins and the overall biochemical properties of this protein ensemble, we suggest that ‘soluble’ PrP can form protein complexes that are maintained by hydrophobic interactions, in a similar manner to lipoprotein vesicles or micellar complexes.

scholarly journals Entrapment of high-molecular-mass DNA molecules in liposomes for the genetic transformation of animal cells

1989 ◽  
Vol 259 (2) ◽  
pp. 549-553 ◽  
Author(s):  
J Szelei ◽  
E Duda
Keyword(s):  
Genetic Transformation ◽  
Molecular Mass ◽  
Mammalian Cells ◽  
Protein Complexes ◽  
Significant Proportion ◽  
High Molecular Mass ◽  
Marker Genes ◽  
Dna Molecules ◽  
Animal Cells ◽  
Integrity Of Dna

We modified the Ca/EDTA procedure for the production of liposomes [Papahadjopoulos, Vail, Jacobson & Poste (1975) Biochim. Biophys. Acta 394, 483-491] to entrap intact DNA molecules of very high molecular mass into large unilamellar phospholipid vesicles. The use of DNA-protein complexes and phage particles instead of naked linear DNA increases the efficiency of entrapment and protects the integrity of DNA molecules. We investigated the interaction of mammalian cells with liposome-encapsulated recombinant lambda bacteriophages carrying marker genes. The liposomes bind surprisingly fast to the cellular surface and are taken up by the cells. A significant proportion of the encapsulated DNA is transported to and soon located in or around the nuclei. Experiments prove that these liposomes can be used for the genetic transformation of mammalian cells.

scholarly journals Two DEAD-Box Proteins May Be Part of RNA-Dependent High-Molecular-Mass Protein Complexes in Arabidopsis Mitochondria

2007 ◽  
Vol 145 (4) ◽  
pp. 1637-1646 ◽  
Author(s):  
Annemarie Matthes ◽  
Stephanie Schmidt-Gattung ◽  
Daniela Köhler ◽  
Joachim Forner ◽  
Steffen Wildum ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Dead Box

scholarly journals Ethylene Receptors Function as Components of High-Molecular-Mass Protein Complexes in Arabidopsis

PLoS ONE ◽  
2010 ◽  
Vol 5 (1) ◽  
pp. e8640 ◽  
Author(s):  
Yi-Feng Chen ◽  
Zhiyong Gao ◽  
Robert J. Kerris ◽  
Wuyi Wang ◽  
Brad M. Binder ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Ethylene Receptors

Post-transcriptional steps involved in the assembly of photosystem I in Chlamydomonas

2004 ◽  
Vol 32 (4) ◽  
pp. 567-570 ◽  
Author(s):  
J.-D. Rochaix ◽  
K. Perron ◽  
D. Dauvillée ◽  
F. Laroche ◽  
Y. Takahashi ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Photosystem I ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Reaction Centre ◽  
Photosynthetic Organisms ◽  
Initiation Of Translation ◽  
Functional Complex ◽  
Rna Protein Complexes ◽  
Photosystem I Complex

Assembly of the PSI (photosystem I) complex in eukaryotic photosynthetic organisms depends on the concerted interactions of the nuclear and chloroplast genetic systems. We have identified several nucleus-encoded factors of Chlamydomonas reinhardtii that are specifically required for the synthesis of the two large chloroplast-encoded reaction-centre polypeptides, PsaA and PsaB, of photosystem I and that function at plastid post-transcriptional steps. Raa1, Raa2 and Raa3 are required for the splicing of the three discontinuous psaA precursor transcripts; they are part of large RNA–protein complexes that are reminiscent of spliceosomal particles. Tab1 and Tab2 are involved in the initiation of translation of the psaB mRNA and are localized in the membrane and stromal phases of the chloroplast, where they are associated with high-molecular-mass complexes. Moreover, two chloroplast-encoded proteins, Ycf3 and Ycf4, are required for the primary steps of assembling the photosystem I subunits into a functional complex.

scholarly journals High molecular mass assemblies of amyloid-β oligomers bind prion protein in patients with Alzheimer’s disease

Brain ◽  
2014 ◽  
Vol 137 (3) ◽  
pp. 873-886 ◽  
Author(s):  
Frank Dohler ◽  
Diego Sepulveda-Falla ◽  
Susanne Krasemann ◽  
Hermann Altmeppen ◽  
Hartmut Schlüter ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Mass ◽  
Prion Protein ◽  
Amyloid Β ◽  
High Molecular Mass

scholarly journals Evolution of the D. melanogaster chromatin landscape and its associated proteins

2018 ◽  
Author(s):  
Elise Parey ◽  
Anton Crombach
Keyword(s):  
Protein Complexes ◽  
Replication Timing ◽  
Fruit Fly ◽  
Biochemical Properties ◽  
Polycomb Group ◽  
A Genome ◽  
Wide Range ◽  
Associated Proteins ◽  
Binary Division ◽  
Inference Methods

AbstractIn the nucleus of eukaryotic cells, genomic DNA associates with numerous protein complexes and RNAs, forming the chromatin landscape. Through a genome-wide study of chromatin-associated proteins in Drosophila cells, five major chromatin types were identified as a refinement of the traditional binary division into hetero- and euchromatin. These five types are defined by distinct but overlapping combinations of proteins and differ in biological and biochemical properties, including transcriptional activity, replication timing and histone modifications. In this work, we assess the evolutionary relationships of chromatin-associated proteins and present an integrated view of the evolution and conservation of the fruit fly D. melanogaster chromatin landscape. We combine homology prediction across a wide range of species with gene age inference methods to determine the origin of each chromatin-associated protein. This provides insight into the emergence of the different chromatin types. Our results indicate that the two euchromatic types, YELLOW and RED, were one single activating type that split early in eukaryotic history. Next, we provide evidence that GREEN-associated proteins are involved in a centromere drive and expanded in a lineage-specific way in D. melanogaster. Our results on BLUE chromatin support the hypothesis that the emergence of Polycomb Group proteins is linked to eukaryotic multicellularity. In light of these results, we discuss how the regulatory complexification of chromatin links to the origins of eukaryotic multicellularity.

scholarly journals Purification and biochemical properties of a high-molecular-mass inositol 1,4,5-trisphosphate 3-kinase isoenzyme in human platelets

1994 ◽  
Vol 298 (3) ◽  
pp. 669-673 ◽  
Author(s):  
D Communi ◽  
V Vanweyenberg ◽  
C Erneux
Keyword(s):  
Molecular Mass ◽  
Specific Activity ◽  
Human Platelet ◽  
Biochemical Properties ◽  
Human Platelets ◽  
High Molecular Mass ◽  
Sds Page ◽  
Inositol 1,4,5 Trisphosphate ◽  
Rapid Purification ◽  
Kinase A

The phosphorylation of inositol 1,4,5-trisphosphate (InsP3) to inositol 1,3,4,5-tetrakisphosphate (InsP4) is catalysed by InsP3 3-kinase. A method is presented for a rapid purification of the enzyme from human platelets. The purified enzyme was identified as a polypeptide of M(r) 69,000-70,000 after SDS/PAGE. It had a specific activity of 1.45 +/- 0.1 mumol/min per mg, and the degree of stimulation by Ca2+/calmodulin was 17-fold at saturating calmodulin and 10 microM free Ca2+. The Km for InsP3 and for ATP was 2.0 microM and 2.5 mM respectively. Human platelet InsP3 3-kinase was not recognized by immunodetection with anti-(InsP3 3-kinase A) or anti-(InsP3 3-kinase B) antibodies. These data provide the first biochemical evidence for the existence of a novel InsP3 3-kinase isoenzyme in human platelets, which is distinct from previously reported InsP3 3-kinase A and InsP3 3-kinase B.

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