HPLC and MS Studies of Orientation of
Melittin on Phospholipid Membrane
NIU Wei,YANG Yu-Feng and SUI Sen-Fang
(1State Key Laboratory of Biomembrane and Membrane
Biotechnology,Tsinghua University,Beijing 100084,China；
WU Yi
Beijing Institute of Microchemistry,Beijing 100091,China )
Abstract The orientation of melittin
binding to liposomes with or without transmembrane potential was investigated.
With a combination of high performance liquid chromatography and mass
spectrometry,the membrane association state of melittin was detected by
analyzing its trypsin-digested products. It was found that the enzyme could
access all the proteolytic sites on protein binding to the liposome without
membrane potential,while one proteolytic site on the N-terminal of the protein
was blocked after it binding to the liposome with negative transmembrane
potential. The results showed that melittin changed its orientation in the
latter case.
Key Words Melittin；orientation on membranes；transmembrane potential；high performance liquid
chromatography(HPLC)；mass spectrometry(MS)
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