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Biomedical subjects

I Bernier

Publications and source records attributed to I Bernier.

At least 19 recordsLinked to original sources
PubMed1987

Complete amino acid sequence of a basic 21-kDa protein from bovine brain cytosol.

The complete amino acid sequence (186 amino acid residues) of a basic cytosolic protein from bovine brain has been determined. It was previously described as a phosphatidylethanolamine binding protein. Computer analyses have been used to calculate its hydropathy profile and to predict its secondary structure. Comparison with other proteins did not detect any significant sequence similarity, except for a short region which presents 53% sequence homology with bovine phosphatidylcholine transfer protein.

Amino Acid Sequence↗
PubMed1986

Ligand-binding studies with a 23 kDa protein purified from bovine brain cytosol.

Ligand-binding studies were performed with a basic 23 kDa protein purified from bovine brain cytosol. By equilibrium dialysis experiments bromosulfophthalein, dehydroepiandrosterone sulfate and oestradiol-17 beta were demonstrated to bind to the protein with association constants of 1 X 10(6), 1 X 10(4) and 1 X 10(3) l/mol, respectively. Indocyanine green, Evans blue and Rose Bengal were not bound. The protein was further characterized as a phosphatidylethanolamine-binding protein, while phospholipid transfer assays proved negative. The so far investigated binding characteristics of the 23 kDa cytosolic protein, together with previously demonstrated sequence homologies with other known cytosolic proteins, suggest its involvement in lipid metabolism.

Animals↗
PubMed1984

Purification and characterization of a basic 23 kDa cytosolic protein from bovine brain.

A soluble basic protein has been purified from bovine brain. It is constituted by a single polypeptide chain with a molecular weight of about 23 kDa and an isoelectric point of about 8.6. The protein was further characterized by its amino-acid composition and by a 39 amino-acid-long N-terminal sequence. Sequence homologies were demonstrated with some other cytosolic proteins. Ligand-binding assays revealed a significant affinity of the 23 kDa protein for bromosulfophthalein. Immunochemical analysis using a rabbit anti 23 kDa brain protein antiserum demonstrated its simultaneous presence in bovine liver as well as in soluble extracts from different origins (mouse and rat brain; human platelets).

Amino Acid Sequence↗
PubMed1982

Presence of cyclic nucleotide-Ca2+ independent protein kinase in bovine brain coated vesicles.

Coated vesicles, which are membrane vesicles enclosed by a polyhedral protein lattice, are involved in many cellular events, including intracellular membrane transport and protein secretion, in which they must be able to undergo repeated membrane fusion and fission. The icosahedral lattice of protein surrounding the core of coated vesicles is composed predominantly of clathrin, a 180,000 (180 K) molecular weight protein, and other 30K and 36K polypeptides. In native conditions, the basic subunit of the coat consists of a trimer of clathrin with probably three polypeptides of 30K and/or 36K (refs 9-11). Additional minor proteins of 100K and 55K have been reported in purified coated vesicles. We describe here the presence of cyclic nucleotide- and Ca2+-independent protein kinase activity in coated vesicles. This protein kinase phosphorylates specifically a unique 50K protein which can be co-purified with clathrin and seems to be an integral protein of coated vesicles.

Animals↗
PubMed1980

Characterization of alpha 1-microglobulin in human colostrum and milk.

The mean concentration of alpha 1-microglobulin in human colostrum and milk, estimated by electroimmunoassay, was found to be about 0.4-0.6 mg/l and 0.1-0.2 mg/l, respectively. Both liquids contained alpha 1-microglobulin in mono- and dimeric forms, while the presence of higher polymeric forms, as characterized in plasma, could not be demonstrated.

Alpha-Globulins↗
PubMed1980

alpha 1-Microglobulin from normal and pathological urines.

alpha 1-Microglobulin was purified from normal and pathological urines. Significant differences were found in the amino acid compositions of the alpha 1-microglobulin isolated from these two sources. In addition electrofocusing of alpha 1-microglobulin from normal urine gave rise to two peaks of equal intensity with rather acidic isoelectric points (3.8 and 4.2), whilst alpha 1-microglobulin from pathological urine showed two peaks in a 1:5 ratio with less acidic isoelectric points (4.2 and 4.7). Further charge heterogeneity was also observed in the second peaks from both sources. The sugar compositions were also established, as well as the N-terminal sequences of the alpha 1-microglobulin of both peaks isolated from normal and pathological urines.

Alpha-Globulins↗
PubMed1979

Immunological and serological data concerning human histocompatibility antigens (HLA) and alpha 1-microglobulin co-purified from urine.

Serologically active glycoproteins (HLA) purified from urine contained only about 4% HLA antigens co-purified with alpha 1-microglobulin. The immunization of rabbits with the serologically active product gave rise to an antiserum containing two kinds of antibodies: anti-HLA-A9 and anti-alpha 1-microglobulin. The anti-HLA-A9 antibodies were detected by the lymphocytotoxicity and indirect immunofluorescence techniques against peripheral blood lymphocytes and cultured lymphoid cell lines. Anti-alpha 1-microblobulin antibodies were detected by immunoprecipitation in gel. Pure alpha 1-microglobulin gave rise to an antiserum directed only against alpha 1-microglobulin. This antiserum did not react with peripheral blood lymphocytes and cultured lymphoid cell lines.

Alpha-Globulins↗
PubMed1978

Molecular data on urinary glycoproteins with human leucocyte antigen (HLA) activity.

Two glycoproteins characterized by their serological activities (HLA-A9 and HLA-B12), their isoelectric points and their molecular weights were purified from urine from a patient suffering from tubular proteinuria (cystinosis). Their physicochemical properties as well as an important increase of their specific activities during the different purification steps suggested that they behave as human leucocyte antigens (HLA) which had been excreted into urine. Their amino acid compositions and N-terminal sequences were different to those described for HLA solubilized from cultured human lymphoblast cell lines. The N-terminal sequences of the two serologically active glycoproteins were identical to the N-terminal sequence of another recently purified human urinary glycoprotein called human complex-forming glycoprotein. The relationship between HLA, human complex-forming glycoprotein and the serologically active urinary glycoproteins is discussed.

Amino Acid Sequence↗
PubMed1977

[Molecular aspects of 2 human urinary glycoproteins with histocompatibility antigen (HLA) serological activity].

Two serologically active urinary glycoproteins (HLA-A 9 and HLA-B 12) were isolated from urine provided by a patient suffering from tubular proteinuria. Their N-terminal sequences were automatically determined. The latter were identical with the sequence of another urinary glycoprotein (protein HC). The relationship between protein HC and the serological activity is discussed.

Amino Acid Sequence↗
PubMed1975

Human platelets as a source of HL-A antigens : a study of various solubilization techniques.

The efficiency of various methods of solubilizing HL-A platelet antigens was investigated. The yield of soluble material was compared with that obtained from lymphocytes in culture in order to judge the quality of platelets as a source of HL-A antigens. The conclusion was reached that platelets, easily obtainable, can be considered as a good source of HL-A antigens.

Blood Platelets↗
PubMed1975

Spontaneous release of soluble HL-A antigens from platelets during conservation.

Experiments with the aim of studying the solubilisation of HL-A antigens from blood platelets by methods which do not involve any biologically active processes (moderate, discontinuous agitation of a low concentration of platelets suspended in a saline medium, in the presence of an antiseptic; supernatants collected at frequent intervals) have shown that platelets release membrane proteins, including HL-A antigens, spontaneously. Optimal conditions for the treatment of membrane proteins have been perfected. The great stability of HL-A antigens under these conditions permits prolonged treatment. The products extracted are soluble and extremely complex. The molecular weight of the HL-A antigens is between 40,000 and 70,000.

Blood Platelets↗