Optically active poly(cis-5-methyl-L-proline) and poly(trans-5-methyl-L-proline) were synthesized from their respective N-carboxy-anhydrides (NCA). Analysis of the i.r., u.v., n.m.r., ORD, and CD spectra of the polymers showed that two different conformations of each polymer exist in the solid and in solution in appropriate solvents. Form I and form II of poly(trans-5-methylL-proline) were foun...

The three proline transporters of Arabidopsis thaliana (AtProTs) transport the compatible solutes proline and glycine betaine and the stress-induced compound γ-aminobutyric acid when expressed in heterologous systems. The aim of the present study was to show transport and physiological relevance of these three AtProTs in planta. Using single, double, and triple knockout mutants and AtProT-overe...

Two L-proline based homochiral frameworks synthesised via diffusion and solvothermal methods display distinct L-proline bonding modes, one N,O chelating and one O,O bridging with amine nitrogen not bound to the metal, with binding mode dependent upon the degree of protonation of the amino acid.

The title compound, C(10)H(15)NO(4), also known as N-tert-butyl-oxycarbonyl-allohydr-oxy-l-proline lactone, is quite similar to N-acetyl-allohydr-oxy-l-proline lactone [Lenstra, Petit & Geise (1979 ▶). Cryst. Struct. Commun. 8, 1023-1029], whereby both carbonyl groups point roughly in the same direction because of the trans conformation of the peptide bond.

Sum frequency generation vibrational spectroscopy (SFG) and quartz crystal microbalance with dissipation monitoring (QCM-D) are employed to study the interfacial structure and adsorbed amount of the amino acids L-lysine and L-proline and their corresponding homopeptides, poly-L-lysine and poly-L-proline, at two liquid-solid interfaces. SFG and QCM-D experiments of these molecules are carried ou...

In the case of actinomycin X2, such reduction leads to formation of actinomycin Cx (IV, L-proline) or actinomycin X0£ (I, threohydroxy-L-proline) and Xod (allohydroxy-Lproline). Previous reports have suggested that oxoproline was destroyed by vigorous hydrolysis of actinomycin X2 with hydrochloric acid and that recovery of the imino acid was achieved in low yield after hydrolysis with hydroiodi...

A series of 4-aryl-6-methyl-3,4-dihydro-2H-pyrano[3,2-c]quinolin-2,5(6H)-diones were synthesized via the three-component reactions of aromatic aldehydes, 4-hydroxy-1-methylquinolin-2(1H)-one, and Meldrum's acid catalyzed by L-proline. The structures of the products were identified by spectroscopic analysis. A mechanism for this three-component reaction catalyzed by L-proline was proposed.

We present a fully defined culture system (adapted Essential8TM [E8TM ] medium in combination with vitronectin) for human embryonic stem cells that can be used for SILAC purposes. Although a complete incorporation of the labels was observed after 4 days in culture, over 90% of precursors showed at least 10% conversion. To reduce this arginine conversion, E8TM medium was modified by adding (1) l...

L-Proline is oxidized to pyrroline-5-carboxylic acid in intact plant mitochondria by a proline dehydrogenase (EC 1.4.3) that is bound to the matrix side of the inner mitochondrial membrane (TE Elthon, CR Stewart [1981] Plant Physiol 67: 780-784). This investigation reports the first solubilization of the L-proline dehydrogenase (PDH) from plant mitochondria. The supernatant from NP-40-treated e...

Clinically used lincosamide antibiotic lincomycin incorporates in its structure 4-propyl-L-proline (PPL), an unusual amino acid, while celesticetin, a less efficient related compound, makes use of proteinogenic L-proline. Biochemical characterization, as well as phylogenetic analysis and homology modelling combined with the molecular dynamics simulation were employed for complex comparative ana...