Heat exchangers are the critical components of refrigeration and liquefaction processes. Selection of appropriate operational conditions for cryogenic recuperative heat exchanger and expansion valve operating in Joule-Thomson cooling system results in improving the performance and efficiency. In the current study, a straightforward procedure is introduced to design an efficient Joule-Thomson co...

The generation of antibodies directed toward the surface-exposed regions of a protein using synthetic peptides as immunogens representing surface loops and turns has been widely successful. However, peptides representing alpha-helical regions are typically unstructured in solution and unable to produce antibodies that recognize alpha-helices in native proteins. We describe a de novo designed pa...

Helical folding of randomly coiled linear polymers is an essential organization process not only for biological polypeptides but also synthetic functional polymers. Realization this dynamic in supramolecular (SPs) is, however, a formidable challenge because their inherent lability main chains upon changing external environment that can drive the (e.g., solvent, concentration, and temperature). ...

Coiled-coil motifs are ubiquitous mediators of specific protein-protein interactions through the formation of interlocking hydrophobic seams between alpha-helical chains. Residues that form these seams occur at the first (a) and fourth (d) positions of a characteristic 7-aa repeat and are primarily aliphatic. The potential of aromatic residues to promote helix association in a coiled coil was e...

The optimal positioning of salt-bridging interactions in a parallel alpha-helical homotrimeric coiled coil has been explored in a metal ion-assembled polypeptide trimer of 60 residues; arginine-glutamate pairs are more stabilizing than the corresponding lysine-glutamate pairs, and optimal stabilization is obtained with positively charged arginine residues at the c positions of the alpha-helical...

Although a helical configuration of a prosthetic vascular graft appears to be clinically beneficial in suppressing thrombosis and intimal hyperplasia, an optimization of a helical design has yet to be achieved because of the lack of a detailed understanding on hemodynamic features in helical grafts and their fluid dynamic influences. In the present study, the swirling flow in a helical graft wa...

Synthetic C peptides, corresponding to the C helix of the HIV type 1 (HIV-1) gp41 envelope protein, are potent inhibitors of HIV-1 membrane fusion. One such peptide is in clinical trials. The crystal structure of the gp41 core, in its proposed fusion-active conformation, is a trimer of helical hairpins in which three C helices pack against a central coiled coil. Each C helix shows especially pr...

The conformations of the helical nucleocapsids of the paramyxoviruses Sendai virus and simian virus 5, and of a rhabdovirus, vesicular stomatitis virus, have been found to vary extensively with changes in salt concentration. In 10 mM sodium phosphate buffer at pH 7.2, the nucleocapsids are loosely coiled or almost completely extended; with increasing concentrations of NaCl they become more tigh...

The modulation of protein-protein interactions (PPIs) by means of creating or stabilizing secondary structure conformations is a rapidly growing area of research. Recent success in the inhibition of difficult PPIs by secondary structure mimetics also points to potential limitations, because often, specific cases require tertiary structure mimetics. To streamline protein structure-based inhibito...

The increased availability of user-friendly and accessible computational tools for biomolecular modeling would expand the reach and application of biomolecular engineering and design. For protein modeling, one key challenge is to reduce the complexities of 3D protein folds to sets of parametric equations that nonetheless capture the salient features of these structures accurately. At present, t...