Crystallographic studies on the binding of selectively deuterated LLD- and LLL-substrate epimers by isopenicillin N synthase
作者:Wei Ge、Ian J. Clifton、Jeanette E. Stok、Robert M. Adlington、Jack E. Baldwin、Peter J. Rutledge
DOI:10.1016/j.bbrc.2010.06.129
日期:2010.8
we report crystallographic studies to investigate the binding of a truncated lll-substrate in the active site of IPNS. Two epimeric tripeptides have been prepared by solution phase peptide synthesis and crystallised with the enzyme. delta-l-alpha-Aminoadipoyl-l-cysteinyl-d-2-amino-3,3-dideuteriobutyrate (lld-ACd(2)Ab) has the same configuration as the natural substrate lld-ACV at each of its three stereocentres;
异青霉素N合酶(IPNS)是一种非血红素铁(II)氧化酶,可催化三肽δ-1-α-氨基己二酰基-1-半胱氨酰-d-缬氨酸(lld-ACV)的生物合成。本文中我们报道了晶体学研究,以研究IPNS活性位点中截短的III-底物的结合。通过溶液相肽合成已经制备了两种表位三肽,并用该酶结晶。δ-1-α-氨基己二酰基-1-半胱氨酰-d-2-氨基-3,3-二氘代丁二酸酯(lld-ACd(2)Ab)在其三个立体中心分别具有与天然底物lld-ACV相同的构型;它的差向异构体δ-1-α-氨基己二酰基-1-半胱氨酰基-1--2-氨基-3,3-二氘代丁二酸酯(III-ACd(2)Ab)在其第三个氨基酸处具有相反的构型。先前已显示III-ACV抑制其底物IId-ACV的IPNS转换。全精制的三肽δ-1-α-氨基己二酰基-1-半胱氨酸-d-2-氨基丁酸酯(lld-ACAb)是IPNS的底物,被转化为Penam和Ceph