Structure of human parathyroid hormone(1-34) in the presence of solvents and micelles.

The structure of the N-terminal 34-residue fragment of human parathyroid hormone was determined in 40% trifluoroethanol employing two-dimensional 1H nuclear magnetic resonance spectroscopy. The proton chemical shifts were assigned from magnitude and phase-sensitive COSY, relayed COSY, and NOESY spectra. Distance constraints, estimated from NOESY spectra, were used to create a set of structures by distance geometry (DGEOM) which were subsequently refined by restrained energy minimization and restrained molecular dynamics (CHARMm).

The effect of recombinant human (1-84) or synthetic human (1-34) parathyroid hormone on the skeleton of adult osteopenic ovariectomized rats.

The purpose of this study was to evaluate the dose-effect relationship of recombinant human PTH [hPTH-(1-84)] and synthetic human PTH [sPTH-(1-34)] for the skeleton of estrogen-deplete osteopenic rats. Ex vivo densitometry of regionalized whole femurs and histomorphometry of proximal tibial cancellous bone were the end points. Retired breeder female rats, aged 6-7 months, were used.

Structure-function studies on bacteriorhodopsin. V. Effects of amino acid substitutions in the putative helix F.

To test structural and mechanistic proposals about bacteriorhodopsin, a series of analogues with single amino acid substitutions has been studied. Mutants in the proposed helix F of bacteriorhodopsin were chosen for investigation because of the probable interaction of this part of the protein with the retinal chromophore. Seven mutants of the bacteriorhodopsin gene were constructed by site-directed mutagenesis, and the gene products were expressed in Escherichia coli.

Thermodynamics of wheat germ agglutinin-sialyloligosaccharide interactions by proton nuclear magnetic resonance.

The thermodynamic parameters that characterize the binding of wheat germ agglutinin isolectin I (WGA I) to the alpha 2-3 isomer of (N-acetylneuraminyl)lactose have been determined by 360-MHz proton nuclear magnetic resonance spectroscopy. The chemical exchange of the ligand between the free and bound sites resulted in a broadening and upfield shifting of the N-acetyl methyl resonance [Kronis, K.A.

Wheat germ agglutinin dimers bind sialyloligosaccharides at four sites in solution: proton nuclear magnetic resonance temperature studies at 360 MHz.

Equilibrium binding studies have been performed over a range of temperatures from 25.4 to 47.3 degrees C between wheat germ agglutinin isolectin I (WGA I) and the alpha 2-3 isomer of (N-acetylneuraminyl)lactose (NeuNAc alpha 2-3Gal beta 1-4G1c).

Specificity of isolectins of wheat germ agglutinin for sialyloligosaccharides: a 360-MHz proton nuclear magnetic resonance binding study.

The binding of three purified sialic acid containing oligosaccharides to two isolectins of wheat germ agglutinin (WGA I and WGA II) has been quantitated by measuring the broadening of a ligand resonance in the proton nuclear magnetic resonance (1H NMR) spectrum at 360 MHz. The ligands, isolated from bovine colostrum by using the procedure of Schneir and Rafelson [Schneir, M. L.