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Biomedical subjects

B Kieffer

Publications and source records attributed to B Kieffer.

43 records · Page 3Linked to original sources
PubMed1988

Amino acid sequence of the ribonuclease inhibitor from porcine liver reveals the presence of leucine-rich repeats.

The primary structure of the ribonuclease inhibitor from pig liver has been determined by amino acid sequence analysis. The N alpha-acetylated polypeptide chain of 456 amino acids consists of 15 homologous leucine-rich repeats, characterized by leucyl residues at constant positions. Two types of alternating repeats occur, 29 (A) and 28 (B) residues long. The degree of identity between repeats of a given type ranged from 25 to 60%. Only one deletion in the B-repeat was necessary to perfectly align the leucyl residues between the two repeats. Leucine-rich repeats have previously been found in four membrane-bound proteins and one extracellular protein, and their amphiphilic character suggested that they could be involved in membrane binding. Ribonuclease inhibitor is the first example of a cytoplasmic protein containing this type of repeat. It seems likely, therefore, that leucine-rich repeats can have functions other than forming membrane binding structures.

Amino Acid Sequence↗
PubMed1986

[Hyalinosis cutis and mucosae. Ultrastructural histochemical aspects indicating intracellular accumulation of glycosaminoglycans].

The exact nature of the genetic defect of hyalinosis cutis et mucosae or d'Urbach-Whiete syndrome is still matter of controversy. The present article reports on three new cases in which several different ultrastructural and biochemical investigations add more arguments to support an anomaly of the glycosaminoglycans degradation in the dermal fibroblasts. Cationic dyes as polyethyleneimine and alcian blue show an intense ultrastructural staining of the abnormal basal laminae and the intracellular lysosomal bodies in cultured fibroblasts. These are related to the accumulation of anionic charged proteoglycans. The primary defect of hyalinosis cutis et mucosae is likely due to a lysosomal defect so far not biochemically defined.

Adolescent↗
PubMedDate not supplied

Modelling the dynamics of an antigenic peptide using NMR relaxation data.

The internal dynamics of a cyclic peptide which was designed to mimic an antigenic loop of the haemagglutinin, is studied through heteronuclear relaxation along the 13C alpha-1H alpha vectors and through homonuclear relaxation along the 1H alpha-1HN and 1H beta-1H beta' vectors. Order parameters are extracted from the longitudinal and cross-relaxation data. Molecular dynamics simulations are performed and the order parameters are calculated in different ways from the trajectories. The simulation, which is performed in vacuo, gives smaller order parameters (vector motions of larger amplitude) than the experimental results. However, the general features of the experimental order parameters are reproduced by the molecular dynamics simulation. The flexibility of the molecule can then be investigated from the results of the molecular dynamics. It shows that the mobility observed through the order parameters is due to motions in flanking regions, remote from the observed vectors.

Amino Acid Sequence↗
PubMedDate not supplied

The pyoverdin receptor FpvA, a TonB-dependent receptor involved in iron uptake by Pseudomonas aeruginosa (review).

Iron is an important element, essential for the growth of almost all living cells. Because of the high insolubility of iron(III) in aerobic conditions, many gram-negative bacteria produce, under iron limitation, small iron-chelating compounds called siderophores, together with new outer-membrane proteins, which function as receptors for the ferrisiderophores. Pseudomonas aeruginosa, an important human opportunistic pathogen, produces at least three known siderophores when grown in iron-deficient conditions: pyochelin, salicylate and pyoverdin. This review focuses on pyoverdin and on the ability of FpvA to bind iron-free and ferric-PaA pyoverdin, in the light of recent information gained from biochemical and biophysical studies and of the recently solved 3D-structures of the related ferrichrome FhuA and enterobactin FepA receptors in Escherichia coli.

Amino Acid Sequence↗
PubMedDate not supplied

[Medico-legal aspects of medical and surgical treatments in venous pathology].

Medical responsibility is subject to progress in the profession and in clinical practice which are continually complicated, although improved, by advances in therapeutic. The effectiveness of the treatment used often ensure a cure for the patients, but the risks involved justify constant surveillance by the clinicians, whose responsibility may be implicated in the event of a therapeutic complication, particularly associated with the use of anticoagulants and surgical procedures in venous pathology. It seemed of interest to draw the attention of specialists in this field to the changing mentality and the consequences on clinical practice.

Aged↗