Characterization of Allosteric Insulin Hexamers by Electrospray Ionization Mass Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 71; no. 2; pp. 384 - 387
• Main Authors: Fabris, D, Fenselau, C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15-01-1999
• Subjects: Aminoacids, peptides. Hormones. Neuropeptides; Analytical, structural and metabolic biochemistry; Biochemistry; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Insulin; Insulin - chemistry; Insulin - metabolism; Mass Spectrometry - methods; Measuring instruments; Molecular Conformation; Phenol - chemistry; Proteins; Zinc - chemistry; Zinc - metabolism; Protein hormone; Pancreatic hormone; Allosteric transition; Investigation method; Insulin; Mass spectrometry; Electrospray
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac980753s

Electrospray mass spectrometry is used at pH 8.0 in combination with accurate mass measurements to confirm the multiplicity of insulin in stable noncovalent complexes with Zn(II) ions. Determination of the nature and number of ligands involved in Zn(II) chelation is in agreement with crystal and solution structures. Counting the number of ligands participating in each center allows deduction of the geometric configuration of the ligand field and gives indirect information about the conformational state of the insulin monomers in solution.