Rabenstein D L, Robert J M, Hari S
Department of Chemistry, University of California at Riverside 92521, USA.
FEBS Lett. 1995 Dec 4;376(3):216-20. doi: 10.1016/0014-5793(95)01286-5.
Evidence is presented that the growth factor glycyl-histidyl-lysine (GHK) binds to heparin, and the interaction has been characterized by [1H]NMR spectroscopy. 1H chemical shifts indicate that GHK interacts with both the carboxylic acid and the carboxylate forms of heparin. The chemical shift data are consistent with a weak delocalized binding of the triprotonated (ImH+, GlyNH3+, LysNH3+) form of GHK by the carboxylic acid form of heparin. As the pD is increased and the carboxylic acid groups are titrated, chemical shift data indicate that ammonium groups of GHK are hydrogen bonded to heparin carboxylate groups, while the histidyl imidazolium ring occupies the imidazolium-binding site of heparin. Evidence for site-specific binding includes displacement of chemical shift titration curves for heparin to lower pD, increased shielding of specific heparin protons by the imidazolium ring current and displacement of chemical shift titration curves for GHK to higher pD. Specific binding constants were determined for binding of the (ImH+, GlyNH3+), LysNH3+) forms of GHK by the carboxylate form of heparin from chemical shift vs. pD titration data.
有证据表明，生长因子甘氨酰 - 组氨酰 - 赖氨酸（GHK）与肝素结合，并且这种相互作用已通过[1H]核磁共振光谱进行了表征。1H化学位移表明GHK与肝素的羧酸形式和羧酸盐形式均发生相互作用。化学位移数据与GHK的三质子化形式（ImH +，GlyNH3 +，LysNH3 +）与肝素的羧酸形式之间的弱离域结合一致。随着pD升高且羧酸基团被滴定，化学位移数据表明GHK的铵基团与肝素羧酸盐基团形成氢键，而组氨酸咪唑环占据肝素的咪唑结合位点。位点特异性结合的证据包括肝素化学位移滴定曲线向较低pD的位移、咪唑环电流对特定肝素质子屏蔽作用的增强以及GHK化学位移滴定曲线向较高pD的位移。根据化学位移与pD滴定数据，确定了GHK的（ImH +，GlyNH3 +）、LysNH3 +形式与肝素羧酸盐形式结合的特异性结合常数。
