Mark Schleyer

Formaldehyde fixation of proteins and small polypeptides after isoelectric focusing in polyacrylamide gels.

Abstract High-sensitivity detection of proteins and small polypeptides after isoelectric focusing is achieved by immersing the polyacrylamide gel directly in an aqueous Coomassie brilliant blue G-250 solution containing 40% methanol and 4% formaldehyde. The carrier ampholytes remain soluble under these conditions, whereas polypeptides over a wide range of molecular masses and isoelectric points are precipitated within the gel matrix.

Das calciumbindende Protein in der menschlichen Darmschleimhaut bei Urämie

SummaryIt could be shown that in uraemic subjects the calciumbinding protein content in duodenal mucosa was 23% less than the corresponding tissue of patients without renal disease. The calcium-binding protein content in uraemic jejunal tissue was even further decreased when compared with normal duodenal tissue. However, there was no normal jejunal tissue available for comparison. The calciumbinding protein was partially purified on Sephadex G-75 and appears by disc electrophoresis as one band, moving rapidly toward the anode. The relationship between these findings and the well known vitamin D resistance in patients with renal disease is discussed.ZusammenfassungDuodenum und Jejunum von 2 urämischen Patienten wurden auf ihren Gehalt an calciumbindenden Protein (CaBP) untersucht und mit gepoolten Duodenalstücken von 10 Nierengesunden verglichen. Das CaBP, über Sephadex G-75 teiweise gereinigt, zeigt in der Discelektrophorese eine rasch zur Anode verlaufende Proteinbande. Die Calciumbindungsfähigkeit (45Ca cpm/mg Protein) der Gewebshomogenate wurde mit dem Chelex-100-Test bestimmt. Die spezifische Calciumbindungsaktivität war im urämischen Duodenum um 23% und im urämischen Jejunum um 34% gegenüber dem Duodenum Nierengesunder vermindert.