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M B Binette

Publications and source records attributed to M B Binette.

6 recordsLinked to original sources
PubMed2000

The proteins and the formation of gallstones.

Cholesterol supersaturation of bile requires assistance to form gallstones. Proteins have been proposed as candidates either to facilitate or hinder the formation of stones. It is assumed that the identity of these stone proteins should be revealed in order to assess their role in the process. We have used electrodialysis of crushed stones to extract the proteins followed by 2D electrophoresis and N-terminal amino acid sequencing to characterize them. The discovery of bacterial proteins in some stones adds evidence to the importance of an inflammatory process and the deconjugation of bilirubin in mixed gallstone formation.

Amino Acid Sequence↗
PubMed1996

Urinary stone proteins: an update.

The discovery of an organic component in kidney stones dates back to 1684. More than 150 years elapsed before the incrustation of this organic component, which is now called the matrix, was proposed as the mechanism of stone formation. The composition of the matrix remained largely unknown until the development of electron microscopy and the advances in biochemistry combined in the 1950's to usher in the modern era of renal stone matrix investigation. Composed mainly of selectively incorporated proteins generally characterized by high glutamic and aspartic acid content and the frequent occurrence of gamma-carboxyglutamic acid, the matrix displays a variable and complex composition and shares a few proteins in many stones. The embryonic stone may first appear in the renal tubules where it can acquire the blood and cell membrane proteins recently found by analysis of stone protein extracts. The combination of supersaturation, an appropriate environment, the availability of calcium binding proteins which may be abnormal, and the incorporation of proteins extracted from leukocytes and cell wall membranes may induce stone formation.

Amino Acid Sequence↗
PubMed1994

Sequencing of proteins extracted from stones.

Proteins from urinary tract and gallbladder stones were extracted and characterized to determine the composition of the matrix and possibly unravel the role of the organic phase in stone formation. Proteins from crushed stones were extracted by electrodialysis and concentrated in the Amicon centricon cartridge or by lyophilization after dialysis against distilled water. Aliquots were first analyzed by isoelectric focusing in gel and if suitable subjected to two-dimensional (2D) electrophoresis. The most promising spots were harvested and the N-terminal amino acids sequenced, thus providing maximum information with minimum expenditure of material. The 2D separations and amino acid sequences of several protein extracts demonstrated similarities and differences in composition and achieved the identification or demonstration of previously and recently detected polypeptides.

Amino Acid Sequence↗
PubMed1993

A cationic protein from a urate-calcium oxalate stone: isolation and purification of a shared protein.

A protein extracted from a urate-calcium oxalate stone by electrodialysis is also excreted in the urine which served as the source material for its purification by FPLC after separation on an ACA44 column. It has an amino acid composition appropriate for a cationic protein. One peptide obtained by cyanogen bromide cleavage has significant (approximately 60%) homology with CD59 protein (protectin). Both proteins have wide distribution, the unknown having been found in bile, cholesterol gallstones, and the wall of the aorta. However, the two proteins appear to be immunologically different.

Amino Acid Sequence↗
PubMed1991

The matrix of urinary tract stones: protein composition, antigenicity, and ultrastructure.

We have extracted proteins from urinary tract stones by electrodialysis and have developed antisera to the core and the shell of a renal stone. The protein composition varies between stones but is identical in the core and the shell of the same stone. One stone antigen is present in the urine of normal individuals and stone formers, as well as in cholesterol gallstone extracts. Electron microscopy of the core of a urate-calcium oxalate stone before and after demineralization reveals a fibrillar structure associated with mineral deposits, as well as aggregates of crystals.

Antibody Formation↗