Aromatic rings exhibit defined interactions via the unique aromatic π face. Aromatic amino acids interact favorably with proline residues via both the hydrophobic effect and aromatic-proline interactions, C-H/π interactions between the aromatic π face and proline ring C-H bonds. The canonical aromatic amino acids Trp, Tyr, and Phe strongly disfavor a polyproline helix (PPII) when they are prese...

Ion mobility spectrometry-mass spectrometry and Fourier transform infrared spectroscopy (FTIR) techniques were combined with quantum chemical calculations to examine the origin of icosahedral clusters of the amino acid proline. When enantiopure proline solutions are electrosprayed (using nanospray) from 100 mM ammonium acetate, only three peaks are observed in the mass spectrum across a concent...

The amino acid proline is uniquely involved in cellular processes that underlie stress response in a variety of organisms. Proline is known to minimize protein aggregation, but a detailed study of how proline impacts cell survival during accumulation of misfolded proteins in the endoplasmic reticulum (ER) has not been performed. To address this we examined in Saccharomyces cerevisiae the effect...

The PutA protein is both the put repressor and a membrane-bound enzyme with proline and delta 1-pyrroline-5-carboxylate dehydrogenase activities. The conditions required for association of purified PutA protein with membrane vesicles suggested that a redox switching mechanism might determine the proportion of PutA protein functioning as a dehydrogenase (Wood, J. M. (1987) Proc. Natl. Acad. Sci....

Proline, an important amino acid, accumulates in many plant species. Besides its role in plant cell responses to environmental stresses, the potential biological functions of proline in growth and development are unclear. Here, we report cloning and functional characterization of the maize (Zea mays) classic mutant proline responding1 (pro1) gene. This gene encodes a Δ1-pyrroline-5- carboxylate...

Less than 5% of the total pool of free amino acids in plants under stress-free conditions is provided by proline. In many plants under various forms of stress, the concentration increases up to 80% of the amino acid pool. This observation raises the question about the molecular mechanisms, making a high proline concentration favourable under stress conditions. Therefore, the literature about th...

Proline metabolism is linked to hyperprolinemia, schizophrenia, cutis laxa, and cancer. In the latter case, tumor cells tend to rely on proline biosynthesis rather than salvage. Proline is synthesized from either glutamate or ornithine; both are converted to pyrroline-5-carboxylate (P5C), and then to proline via pyrroline-5-carboxylate reductases (PYCRs). Here, the role of three isozymic versio...

The main protein in alveolar bone and dentin is collagen.' Two thirds of the total amino acids found in collagen are composed of glycine, alanine, proline, and hydroxyproline.' The hydroxyproline in collagen is derived almost exclusively from hydroxylation of proline. Thus the proline molecule may enter collagen in two ways: as proline or as hydroxyproline.2 4 Many studies have used radioactive...