Membrane-binding两性α螺旋肽来源于CTP:胆碱磷酸cytidylyltransferase。
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康奈尔大学约翰逊我,RB
Membrane-binding两性α螺旋肽来源于CTP:胆碱磷酸cytidylyltransferase。
生物化学。1994年4月12日,33 (14):4327 - 35。
- PubMed ID
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8155650 (在PubMed]
- 文摘
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肽对应于两性α螺旋的一部分地区的CTP:胆碱磷酸cytidylyltransferase合成。提出了这一地区的酶是membrane-binding域[G.B.卡马尔凯,效力物等,。Aebersold, R。&康奈尔,R.B. (1990) Proc。国家的。学会科学。美国87年、6029年)。我们已经证明,肽在物理上与PG囊泡相关联。CD缓冲主要提出了随机肽的结构,同时,在trifluoroethanol面前,α螺旋肽。阴离子脂质囊泡了一个α螺旋构象,而中性或阳离子脂质囊泡不改变随机肽的结构,表明选择性α螺旋的稳定阴离子膜。 The fluorescence of the single tryptophan residue, which lies on the hydrophobic face of the amphipathic alpha-helix, was studied. Anionic lipid vesicles specifically induced a shift in the fluorescence to a lower wavelength. Fluorescence quenching by the aqueous-phase quencher, I-, and the lipid-phase quencher 9,10-dibromo-PC was used to determine the accessibility of the tryptophan to each of these environments. The presence of anionic lipid vesicles, but not nonanionic lipid vesicles, decreased the quenching by I- suggesting that, in the presence of anionic lipids, the tryptophan residue is poorly accessible to the aqueous I-. Dibromo-PC significantly quenched the fluorescence only when present in anionic vesicles, confirming the membrane location of the tryptophan residue and the lipid specificity of this interaction.(ABSTRACT TRUNCATED AT 250 WORDS)