Structural characterization of peptide fragments from hCD81-LEL
Structural characterization of peptide fragments from hCD81-LEL
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DOI：
10.1034/j.1399-3011.2003.00038.x
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发表时间：
2003-02-01
期刊：
影响因子：
--
通讯作者：
Prakash, O
中科院分区：
文献类型：
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作者：
Dhanasekaran, M;Baures, PW;Prakash, O
The solution conformation of two peptides [1: PSGSNparallel toSNLFKED; 2: GSSTLTALTTSVLKNNL] from human CD81 (hCD81) large extra-cellular loop (LEL) with known importance in the hepatitis C virus glycoprotein E2 (HCV-E2) binding interaction was characterized using circular dichroism spectroscopy. In addition, the solution structure of peptide 1 that contains a phenylalanine residue (F186 in hCD81) known to be critical in the binding interaction with HCV-E2 was determined using 1 D and 2D H-1 NMR spectroscopy. Both peptides are unstructured in water but begin forming significant helical conformation following the addition of 20% or more trifluoroethanol (v/v), a result consistent with their alpha-helical conformation found in the native protein. The CD data recorded as a function of pH and NaCl concentration are consistent with stabilization of the helical structure from electrostatic forces for both peptides. Peptide 1 is able to block the binding interaction of recombinant HCV-E2 (rHCV-E2) to hCD81 expressed on Molt-4 T cells at high concentrations (3.5 mm), a low affinity that we attributed to the random coil structure in water.
