Role of lipids in the Neurospora crassa membrane: III. Lipid composition and phase transition properties of the plasma membrane, and its components.

摘要: TheNeurospora crassa mutantslime, which lacks a cell wall, was used to determine the lipid composition and phase transition properties of plasma membrane its components. The were then compared same parameters whole extracts ofNeurospora slime. Phospholipids extracted from cells membranes have similar fatty acid profiles, but differ somewhat in phospholipid base compositions. These differences profiles not sufficient cause heat content (ΔH) or mid-point temperature phospholipids' gel-liquid crystal transitions as detected by scanning calorimetry. Phase temperatures contents for −23.8 −22.5°C 0.3 1.7 cal/g, respectively. Commercially available phospholipids when mixed ratios found yielded results: “model” system extract had −22°C ΔH=1.1 with −21°C ΔH=1.24 cal/g. neutral fraction also exhibits endothermic activity calorimeter at below 0°C ΔH∼9 Total preparations (neutral+phospholipids) freezedried scanned excess water do exhibit any events calorimeter. Neutral lipids probably interact abolish calorimetrically detectable phospholipids. Whole are sufficiently permit use model studying effect altered on physical theNeurospora membrane.