Model protein surface domains for the investigation of metal ion-dependent macromolecular interactions and biospecific metal ion transfer*1

摘要: We describe the use of surface-immobilized transition metal ions not only as tools for site-specific immobilization and purification peptides proteins but also probes altered macromolecular surface architecture. Although we present examples traditional immobilized chemical chelators (e.g., iminodiacetate) these purposes, introduce methods identifying using natural metal-binding domains derived from protein surfaces to immobilize in a biospecific manner. Such model facilitate investigation mechanisms by which influence interaction macromolecules. This approach, domain recognition, depends on proficient identification characterization individual domains. To this process, have developed two different forms soft ionization mass spectrometry observe intact peptide-metal ion complexes; enables mass-dependent specific sequences. Model constructed thus far found exhibit ion-dependent recognition specificity include (i) series (GHHPH)nG, define (G365-H389) human plasma transport known histidine-rich glycoprotein; (ii) dimerization (D473-L525) estrogen receptor protein; (iii) “zinc-finger” DNA-binding (K180-M250) receptor; (iv) iron-binding (R1-K18) N-terminus β-casein. discuss interactions between macromolecules transfer