Metastability in the phase behavior of dimyristoylphosphatidylethanolamine bilayers.
Metastability in the phase behavior of dimyristoylphosphatidylethanolamine bilayers.
复制标题
二肉豆蔻酰磷脂酰乙醇胺双层相行为的亚稳定性。
DOI：
10.1021/bi00302a030
复制
发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
Nagle,JF
中科院分区：
文献类型：
--
作者：
Wilkinson,DA;Nagle,JF
材料和方法本研究中使用的磷脂酰乙醇胺来自 Calbiochem-Behring Corp. 和 Avanti Biochemicals。扫描实验中观察到的主跃迁的半宽度足够小（< 0.5 K），以确保样品的高纯度。样品的适当水合至关重要（Mantsch 等人，1983）并按如下方式进行。向称重的干脂质粉末中添加水或20 mM缓冲液（磷酸盐，pH 7.0）以产生悬浮液，其浓度对于膨胀测定为2-3%，对于量热测定浓度为0.1%。将脂质和缓冲液加热至70°C几分钟，剧烈涡旋约30秒，然后冷却至30°C。该加热-冷却过程再重复3次。作为温度或时间函数的比体积通过使用差示膨胀计来测定（Wilkinson & Nagle，1978）。使用 Microcal MC-1 (Amherst, MA) 差示扫描量热计进行量热测定。对于膨胀测定采用3-4℃/h的加热速率，对于量热测定采用10℃/h的加热速率。
Materials and MethodsThe phosphatidylethanolamines used in this study were obtained from Calbiochem-Behring Corp. and Avanti Biochemicals. The half-widthsof the main transition observed in scanning experiments were sufficiently small (< 0.5 K) to assure high purity of samples. Proper hydration of the samples is critical (Mantsch et al., 1983) and was performed as follows. To the weighed drylipid powder was added either water or 20 mM buffer (phosphate, pH 7.0) to produce suspensions whose concentrations were 2-3% for dilatometry and 0.1% for calorimetry. The lipid and buffer were heated to 70 C for several minutes, vortexed vigorously for approximately 30 s, and then cooled to 30 C. This heating-cooling procedure was repeated an additional3 times. The specific volume as a function of temperature or time was determined by using a differential dilatometer (Wilkinson & Nagle, 1978). Calorimetry was performed with a Microcal MC-1 (Amherst, MA) differential scanning calorimeter. Heating rates of 3-4 C/h for dilatometry and 10 C/h for calorimetry were employed.