Several investigators have reported that commercial L-proline is contaminated with small amounts of hydroxy-n-proline (l-3). During the course of investigations in this laboratory all of five commercial samples proved to contain up to 3.5 per cent hydroxyproline when tested by the method of Neuman and Logan (1). The preparation of n-proline from gelatin by the formation of complex salts is tedi...

Purified brush-border membrane vesicles (BBMV) of starfish [Pycnopodia helianthoides (Brandt)] pyloric caecal epithelium were prepared by magnesium precipitation in order to characterize the possible role of this organ in amino acid transport. L-[H]proline uptake by these vesicles was Na-dependent and greater at pH7.5 than at pH5.5. L-Pipecolate was a competitive inhibitor of L-proline influx i...

UNLABELLED Prolyl 4-hydroxylase (EC 1.14.11.2) catalyzes the hydroxylation of -X-Pro-Gly- sequences and plays a central role in the synthesis of all collagens. The [alpha(I)]2beta2 type I enzyme is effectively inhibited by poly(L-proline), whereas the [alpha(II)]2beta2 type II enzyme is not. We report here that the poly(L-proline) and (Pro-Pro-Gly)10 peptide substrate-binding domain of prolyl 4...

Ling, Chung-Mei (Illinois Institute of Technology, Chicago), and L. R. Hedrick. Proline oxidases in Hansenula subpelliculosa. J. Bacteriol. 87:1462-1470. 1964-Cells of Hansenula subpelliculosa can use l-proline as a carbon and a nitrogen source after a 6- to 8-hr induction period. However, they cannot use l-glutamate as both nitrogen and carbon sources unless the induction period is of several ...

Completing our reports concerning the reaction products from calcium halides and the amino acid proline, two different solids were found for the reaction of l- and dl-proline with CaI2. The enanti-opure amino acid yields the one-dimensional coordination polymer catena-poly[[aqua-μ3-l-proline-tetra-μ2-l-proline-dicalcium] tetra-iodide 1.7-hydrate], {[Ca2(C5H9NO2)5(H2O)]I4·1.7H2O} n , (1), with t...

The asymmetric unit of the title compound, [Hg(4)Cl(8)(C(5)H(9)NO(2))(2)](n), consists of four HgCl(2) units and two L-proline ligands in the zwitterionic form. In each HgCl(2) unit, the Hg(II) ion is strongly bonded to two Cl atoms, and the Hg(II) ions in two of the HgCl(2) units are chelated by O atoms of two l-proline ligands, with one strong and one weak Hg-O bond. In the crystal structure,...

Renal tubular absorption of the free amino acids L-proline, hydroxy-L-proline, and glycine in man is accomplished by a transport system exhibiting preference for this group of amino acids (1, 2). The characteristics of saturability (for L-proline transport) and selective inhibition between the constituent substrates have been demonstrated for this system in man (1). Studies in vivo in the rat (...