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This paper describes a methodology that correlates experimental chemical shifts (at the alpha proton) of proteins with their geometrical data (both dihedral angles and distances) obtained from 13 representative proteins, which are taken from the Protein Data Bank (PDB) and the BioMagRes Data Bank (BMRB). To this end, the experimentally measured proton chemical shifts of simple amides have been correlated with DFT-based calculated structures, at the B3PW91/6-31G* level. This results in a series of mathematical relationships, which are extrapolated to the above-mentioned proteins giving rise to a modified equation for such skeleta. It is relevant to note that the equation is also supported by a clear comparison with NMR data of a protein beyond the chosen set, such as insulin, even with lower errors. The model also relates the dependence of chemical shifts on hydrophobic and anisotropic effects at the amino acid residues.

Substances that mediate the import of proteins into cells, "carriers", have many potential applications. The most potentially useful carriers do not have to be covalently linked to their protein cargoes. However, a common problem with all carrier molecules is that they tend to deposit the cargo proteins into endosomes; diffuse distribution in the cytosol is the desired outcome. This paper describes the import of four different labeled (Alexa Fluor 488) proteins (avidin, recombinant streptavidin, bovine serum albumin, and beta-galactosidase), with the well-known non-covalent carrier called pep-1 (also known as Chariot), with R(8) (a molecule that is not widely appreciated to import protein cargoes via a non-covalent mode of action), and with a new molecule called azo-R(8). The data collected from fluorescence microscopy and flow cytometry indicate that all three non-covalent carriers can facilitate transport. At 37 degrees C, import into endocytic compartments dominates, but at 4 degrees C weak, diffuse fluorescence is observed in the cytosol, indicative of a favorable mode of action.