Solution structure of a human calcitonin analog elucidated by NMR and distance geometry calculations.

Three-dimensional structure of a human calcitonin analog (abbreviated as hCTa) in which the amino acids of the wild type are replaced at position 12, 16 and 19 by leucine residues and further at position 22 by a tyrosine residue was studied in TFE solution by 1H-NMR and distance geometry calculations. This analog has a 15-20 times activity as compared with the wild type. The amino acid replacements resulted in formation of an amphiphilic alpha-helix in the region between the residues 4-20. The overall three-dimensional structure is similar to that of the wild type. The conformational feature of hCTa with a hydrophobic face composed with a Met and four Leu residues may be related to its higher hypocalcemic potency.

Preliminary nuclear magnetic resonance studies on human saliva.

Of gustatory-stimulated human whole, parotid, submandibular and sublingual saliva only parotid saliva, a serous rather than mucous secretion, presented a relatively well-resolved proton NMR spectrum with satisfactory signal-to-noise ratio in a short time (30 min). The proton signal intensities showed significant circadian rhythms related to the circadian rhythms of protein concentrations in saliva. Age- and sex-associated differences in spectra were not observed for healthy saliva. On the other hand, marked differences in the spectra were observed for patients with suspected sialoadenitis.