Gupta C M, Radhakrishnan R, Gerber G E, Olsen W L, Quay S C, Khorana H G
Proc Natl Acad Sci U S A. 1979 Jun;76(6):2595-9. doi: 10.1073/pnas.76.6.2595.
Phospholipids containing photolysable carbene precursors (beta-trifluoro-alpha-diazopropionoxy and m-diazirinophenoxy groups) in omega-positions of sn-2 fatty acyl chains were prepared. Photolysis of their vesicles produced crosslinked products in 40-60% yields. Crosslinking was mostly intermolecular and occurred by carbene insertion into the C-H bonds of a second fatty acyl chain. Crosslinking products were characterized by (i) their gel permeation behavior, (ii) analysis of products formed by base-catalyzed transesterification, (iii) degradation with phospholipases A2 and C, (iv) gas chromatography/mass spectrometry, and (v) use of mixtures of phospholipids carrying the carbene precursors and a phospholipid containing radioactively labeled fatty acyl groups. Nitrenes generated from the aliphatic or aromatic azido groups in phospholipids were unsatisfactory for forming crosslinks by insertion in C-H bonds.
制备了在sn-2脂肪酰链的ω位含有可光解卡宾前体(β-三氟-α-重氮丙氧基和间重氮苯氧基)的磷脂。其囊泡的光解产生了产率为40-60%的交联产物。交联大多是分子间的,通过卡宾插入第二条脂肪酰链的C-H键发生。交联产物通过以下方法进行表征:(i) 它们的凝胶渗透行为,(ii) 碱催化酯交换形成的产物分析,(iii) 用磷脂酶A2和C进行降解,(iv) 气相色谱/质谱分析,以及(v) 使用携带卡宾前体的磷脂与含有放射性标记脂肪酰基的磷脂的混合物。由磷脂中的脂肪族或芳香族叠氮基团产生的氮烯不能通过插入C-H键形成交联,效果不理想。