The magnesium-ion-dependent cleavage of the vinyl ether linkage of brain ethanolamine plasmalogen

1. There was a significant decrease in the amount of endogenous ethanolamine phospholipids when preparations of whole brain were incubated in bicarbonate–Ringer solutions, leading in particular to the hydrolysis of vinyl ether groups. 2. The hydrolysis of ethanolamine phospholipids in such preparations was abolished in the absence of bivalent cations. 3. An enzyme present in extracts of acetone-dried brain powders that cleaved the vinyl ether linkage in ethanolamine plasmalogen maximally at pH 7·4 required Mg²⁺ for activity. 4. The cleavage of the vinyl ether linkage of an ethanolamine lysoplasmalogen was enhanced in the presence of Mg²⁺ but the requirement was not absolute.     

The effect of protease digestion (in situ) on the slime substance of mature sieve tubes

Summary The sieve tube slime of Tetragonia and Lycopersicum petiolar phloem was subjected to proteolytic enzymes both before and after embedding and sectioning. Subsequent electron microscopical examination confirmed that the fibrillar material is protein in nature, and provided evidence that the protein is acidic rather than basic.     

Der Bauchsympathicus der Blindschleiche und seine Beziehungen zur Innervation der Niere

Ohne Zusammenfassung     

The hydrolysis of glycerophosphocholine by rat brain microsomes: Activation and inhibition

Experiments with glycerophosphocholine phosphodiesterase (GPC diesterase, EC 3.1.4.2.) in rat brain microsomes suggest that, although its activity is inhibited by low concentrations of calmidazolium, its dependence on Ca²⁺ ions is not modulated by calmoulin. The activity of glycerophosphocholine choline phosphodiesterase (choline phosphohydrolase, EC 3.1.4.38) was much lower than that of the GPC diesterase. A relatively inexpensive method for the preparation ofsn-glycero-3-phospho [Me-¹⁴C]choline is described.Special Issue Dedicated to Dr. Abel Lajtha.