The rapid increase of the number of sequenced genomes asks for the functional annotation of the encoded enzymes. We used a combined computational-structural approach to determine the function of the TrpB2 subgroup of the tryptophan synthase β chain/β chain-like TrpB1-TrpB2 family (IPR023026). The results showed that TrpB2 enzymes are O-phospho-l-serine dependent tryptophan synthases, whereas Tr...

The responses of female noninbred mouse urinary bladder ornithine decarboxylase (EC 4.1.1.17) (ODC) and S-adenosylu-methionine decarboxylase (EC 4.1.1.50) (SAMD) activities to L-tryptophan feeding and to topical intraurethral administration of L-tryptophan and some of its urinary metabolites were stud ied. Mice fed a diet containing 1% L-tryptophan demonstrated significant increases in vesical ...

Evaluating the formation of tryptophan glycoconjugates other than well-established Amadori rearrangement products, HPLC-tandem MS (MS/MS) analysis of human urine collected from several healthy individuals proved the presence of one distinct tryptophan C-glycosyl compound [Horiuchi, Yonekawa, Iwahara, Kanno, Kurihara and Fujise (1994) J. Biochem. (Tokyo) 115, 362-366]. After isolation, unambiguo...

Both co-ordinate and sequential inductions govern the synthesis of the enzymes required for the oxidative dissimilation of L-tryptophan by a strain of Pseudomonas$zlorescerrs. The first two enzymes of the sequence, tryptophan pyrrolase and formylkynurenine formamidase, are induced co-ordinately by L-kynurenine, the product of their successive action on L-tryptophan; L-tryptophan itself is not a...

Nosocomial infections with enterococci are an increasing problem in modern medical practice due to the development of resistance to a wide range of antibiotics, including the glycopeptides vancomycin and teicoplanin. An increasing number of vancomycin-resistant enterococci (VRE) have been cultured from clinical specimens -- especially from patients undergoing immunosuppressive therapy -- and ba...

Reports from several laboratories have shown that cats display a peculiar tryptophan metabolism as compared with other mammals. In 1941, Kotake and Nakayama (1) reported that L-kynurenine could be quantitatively converted to anthranilic acid when incubated with cat liver preparations. Gordon, Kaufman, and Jackson (a), on the other hand, found no kynurenic acid in urine of cats even when tryptop...

Tryptophan catabolism via the enzyme indoleamine 2,3-dioxygenase (IDO) allows human monocyte-derived macrophages (MDM) and other APC to suppress T cell proliferation. IDO helps protect murine fetuses from rejection by the maternal immune system and can promote tolerance and immunosuppression. For tryptophan to be catabolized by IDO, it must first enter the APC via transmembrane transport. It ha...