The quality of classical biomolecular simulations is inevitably limited by two problems: the accuracy of the force field used and the comprehensiveness of configuration space sampling. In this work we tackle the sampling problem by carrying out driven adiabatic free energy dynamics to obtain converged free energy surfaces of dipeptides in the gas phase and in solution using selected dihedral an...

A perfusion technique has been used to quantitate the effect of the amino acids glycine and alanine and the dipeptides glycyl-glycine and glycyl-L-alanine on sodium and water absorption from the human jejunum. Although no net absorption of sodium and water was seen in the absence of non-electrolytes, a significant stimulation occurred in the presence of both free amino acids and dipeptides. In ...

1. The absorption of lysine and two lysine-containing dipeptides was studied in normal and cystinuric subjects by jejunal perfusion. Absorption of each dipeptide was compared with that of its constituent amino acids. 2. In normal subjects lysine was better absorbed from the dipeptide glycyl-L-lysine than from the equivalent amino acid mixture. In cystinuric patients lysine was absorbed very poo...

MHC class I molecules bind only those peptides with high affinity that conform to stringent length and sequence requirements. We have now investigated which peptides can aid the in vitro folding of class I molecules, and we find that the dipeptide glycyl-leucine efficiently supports the folding of HLA-A*02:01 and H-2K(b) into a peptide-receptive conformation that rapidly binds high-affinity pep...

In order to determine whether bovine, rabbit, and monkey myelin basic proteins (BPs) have the sequence Gly-His or His-Gly at positions corresponding to bovine sequence 76-77, we isolated the tryptic peptides encompassing the sequence in question in these proteins and cleaved them into dipeptides with dipeptidyl aminopeptidase I (EC 3.4.14.1). Analysis by gas chromatography/mass spectrometry of ...

The synthesis of novel oxetanyl peptides, where the amide bond is replaced by a non-hydrolyzable oxetanylamine fragment, is reported. This new class of pseudo-dipeptides with the same H-bond donor/acceptor pattern found in proteins expands the repertoire of peptidomimetics.