The intrinsic polymer properties of glycine-rich sequences are evaluated with a set of iso-1-cytochrome c variants with N-terminal inserts of the sequence (GGGGGK)(n) for n = 1-5. The thermodynamics and kinetics of His-heme loop formation are measured as a function of guanidine hydrochloride (GdnHCl) concentration for loop sizes ranging from 22 to 46 residues. The scaling exponent for loop form...

We show how iron and copper ions may be simultaneously measured in 0.2 ml of serum after using guanidine hydrochloride to cause their release from protein. Sensitive reagents for iron (2,4,6-tripyridyl-s-triazine) and copper (disodium 2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline disulfonate) facilitate such measurement. We eliminated spectral interference between the two metal-ion complexes b...

Peptide mapping of antibodies is an essential method to monitor peptide modifications in antibody lots that could affect the safety and efficacy product. Conventional protocols rely on protein digestion using proteases, such as trypsin, before with mass spectrometry (MS). However, trypsin may cause incomplete peptides, especially those include highly hydrophobic peptides. Here, we show how peps...