从七肽噬菌体展示库中筛选蛋白质配基

为了研究噬菌体展示技术的应用，以溶菌酶为靶分子从七肽噬菌体展示库中筛选蛋白质的高亲和力噬菌体配体，所筛选的亲和力最高的噬菌体的ELISA检测值A405nm可达0．634．通过比较亲和性噬菌体外源插入肽的DNA序列，认为基元HWWW是肽段与酶分子发生亲和的必需序列．此外，由于靶分子和高亲和性展示肽的等电点分别为11．2和6．74，因此在亲和环境中携带异种电荷，利于亲和吸附的发生，而此时低亲和性展示肽与靶分子携带同种电荷，阻碍了亲和吸附．同时，高亲和性肽段HWWPAS和与其有较高同源性的肽段HWTWWNL都有适中的疏水性，这有利于肽与靶分子表面的疏水位点相互作用从而产生亲和吸附．

Selection of Ligand from a Heptapeptide Phage Display Library for Lysozyme

The high affinity phage-ligand of a lysozyme was selected from 7-mer phage display library. The ELISA signal of the highest affinity clone at 405 nm was found to reach 0.634.The comparison of the amino acid sequences of foreign peptides of the clones shows specificity to lysozyme molecules,and the HWWW motif is considered to be the necessary amino acid sequence for the affinity. The isoelectric point of the target molecule and the high affinity peptide were 11.2 and 6.74 respectively,so they will bring different charges in the affinity condition,which enable the affinity binding occur more easily.Contrastively,the two low affinity peptides bring the same charge as target molecule,which will disturb the affinity binding between the target molecule and peptide.In additional,both the high affinity peptide HWWWPAS and the other peptide HWTWWNL that has higher homology to HWWW PAS,have moderate hydrophobicity that might help the peptides binding to certain bydrophobic sites on the surface of target molecule.