Synthetic cross-links arrest the C-terminal region of the relaxin-like factor in an active conformation.
Synthetic cross-links arrest the C-terminal region of the relaxin-like factor in an active conformation.
复制标题
合成交联将松弛素样因子的 C 末端区域抑制在活性构象中。
DOI：
10.1021/bi049601j
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Schwabe,Christian
中科院分区：
文献类型：
--
作者：
Bullesbach,ErikaE;Schwabe,Christian
所有动力学指标均表明松弛素样因子 (RLF) 的受体结合位点位于 B 链的柔性 C 末端区域，并且以 B27 位色氨酸为中心。使用不同长度的构象限制将色氨酸 (B27) 限制在相对于 A 链 C 末端的狭窄位置范围内。涉及色氨酸 (B27) 附近残基的变体的全合成向我们保证，没有一个变体在受体结合中发挥作用。即使是仅次于重要色氨酸的精氨酸 B26，也可以被替换而不会产生有害影响。为了将 A 链 C 末端和色氨酸 (B27) 之间的距离固定在预定长度，我们合成了在位于 B26 位的赖氨酸和 A 链 (A26) C 末端的 α-羧基之间具有共价交联的 RLF。交联配体对 RLF 受体的亲和力随着长度的抛物线函数而变化，其中 10.0−11.1 Å 的范围提供了最接近结合构象的方法。通过 cAMP 积累确定的野生型跨膜信号传导活性仅通过甘氨酸交联剂才能达到。
All kinetic indicators suggest that the receptor-binding site of the relaxin-like factor (RLF) is located in the flexible C-terminal region of the B chain and is centered about the tryptophan in position B27. Conformational restraints of varying lengths were used to confine Trp (B27) to a narrow range of positions relative to the C terminus of the A chain. Total synthesis of variants involving residues proximate to Trp (B27) assured us that none had a role in receptor binding. Even arginine B26, next to the important tryptophan, can be replaced without deleterious effects. To fix the distance between the C-terminal end of the A chain and Trp (B27) at predetermined lengths, we synthesized RLF with covalent cross-links between a lysine, which was placed in position B26, and the α-carboxyl group at the C terminus of the A chain (A26). The affinity of the cross-linked ligands for the RLF receptor varied as a parabolic function of length whereby the range of 10.0−11.1 Å provided the closest approach to the binding conformation. Wild-type transmembrane signaling activity, as determined by cAMP accumulation, was reached only with a glycine cross-linker.