Shi Y L, Wang W P, Zhang H, Xu K
Shanghai Institute of physiology, Academia Sinica.
Sheng Li Xue Bao. 1992 Dec;44(6):533-40.
Using planar lipid bilayer formed by lecithin and cholesterol (20 and 5 mg/ml respectively in N-decane) the channel-forming activity of the membrane active polypeptide B(BMAP B) from the venom of Bungarus fasciatus was investigated. Under the existence of a voltage or a salt concentration gradient between two sides of the bilayer, unit conductance fluctuation and a decrease in steady state resistance accompanying BMAP B incorporation and channel formation were observed. By measuring the reversal potential in an asymmetric solution, the selectivity of the BMAP B-channel was estimated having a value of PK/PC1 = 1.4. Divalent cations, such as Ba2+, Ca2+ inhibited the channel activity as they did in biomembranes. These data might provide an explanation for the depolarizing effect of the membrane active polypeptide on the native membranes.
利用由卵磷脂和胆固醇（分别在正癸烷中为20毫克/毫升和5毫克/毫升）形成的平面脂质双层，研究了银环蛇毒液中膜活性多肽B（BMAP B）的通道形成活性。在双层两侧存在电压或盐浓度梯度的情况下，观察到伴随BMAP B掺入和通道形成的单位电导波动以及稳态电阻的降低。通过测量不对称溶液中的反转电位，估计BMAP B通道的选择性值为PK/PC1 = 1.4。二价阳离子，如Ba2+、Ca2+，像在生物膜中一样抑制通道活性。这些数据可能为膜活性多肽对天然膜的去极化作用提供一种解释。
