Gettins P
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
J Biol Chem. 1988 Jul 25;263(21):10208-11.
Complexes between phosphoramidon (N-(alpha-rhamnopyranosyloxyhydroxyphosphinyl)-L-leucyl-L-tryptoph an) and zinc thermolysin and between phosphoramidon or N-phosphoryl-L-leucineamide and 113Cd-substituted thermolysin have been examined by 31P and 113Cd NMR spectroscopy. 113Cd resonances are observed at 168 and 152 ppm for the phosphoramidon and N-phosphoryl-L-leucineamide complexes, respectively. There are large but different chemical shift anisotropy contributions to the 113Cd line widths for the two complexes, which reflect the known structural differences for the zinc-enzyme complexes. 113Cd-31P spin-spin coupling is also seen and differs for the two cadmium complexes, being larger, 28 Hz, for the bidentate N-phosphoryl-L-leucineamide ligand than for the monodentate phosphoramidon, 16 Hz. Large changes in chemical shift, 7.5-10.9 ppm, are seen for the 31P resonances of the inhibitors upon binding to the enzyme reflecting direct phosphoryl-metal ligation. Chemical shift anisotropy is the dominant relaxation mechanism for the 31P nuclei at 9.4 T, while the dipole-dipole contribution seems to be unaffected by a change of solvent from H2O to D2O.
已通过³¹P和¹¹³Cd核磁共振光谱法研究了磷酰胺脒（N-（α-鼠李糖基氧基羟基膦酰基）-L-亮氨酰-L-色氨酸）与锌嗜热菌蛋白酶之间以及磷酰胺脒或N-磷酰-L-亮氨酸酰胺与¹¹³Cd取代的嗜热菌蛋白酶之间的复合物。对于磷酰胺脒和N-磷酰-L-亮氨酸酰胺复合物，¹¹³Cd共振分别出现在168 ppm和152 ppm处。两种复合物的¹¹³Cd线宽存在很大但不同的化学位移各向异性贡献，这反映了锌酶复合物已知的结构差异。还观察到¹¹³Cd-³¹P自旋-自旋耦合，并且两种镉复合物的该耦合不同，对于双齿N-磷酰-L-亮氨酸酰胺配体，该耦合较大，为28 Hz，而对于单齿磷酰胺脒，为16 Hz。抑制剂与酶结合后，其³¹P共振的化学位移发生了7.5 - 10.9 ppm的大幅变化，这反映了直接的磷酰-金属配位。在9.4 T时，化学位移各向异性是³¹P核的主要弛豫机制，而偶极-偶极贡献似乎不受溶剂从H₂O变为D₂O的影响。
