Previously, we identified DPTH, an analogue of antiepileptic drug phenytoin (5,5-diphenylhydantoin, DPT), capable of retarding the cell cycle in the human vascular endothelial cells. Our data suggest that DPTH inhibits human umbilical venous endothelial cells (HUVEC) proliferation by increasing the level of p21 protein, which in turn inhibits the activities of cyclin-dependent kinase (CDK)2 and...

The role of the tryptophan-metabolizing enzyme indoleamine 2,3-dioxygenase (IDO) in down-regulating human alloresponses has recently been controversially debated. We here demonstrate that human monocyte-derived dendritic cells (mDCs) can be endowed with sustained IDO competence in vitro by 48-hour activation with lipopolysaccharide (LPS) and interferon-gamma (IFN). IFNalso amplified proinflamma...

Renal cell carcinoma (RCC) is increasing in incidence, and a complete cure remains elusive. While immune-checkpoint antibodies are promising, interferon-based immunotherapy has been disappointing. Tryptophan metabolism, which produces immunosuppressive metabolites, is enhanced in RCC. Here we show indolamine-2,3-dioxygenase-1 (IDO1) expression, a kynurenine pathway enzyme, is increased not only...

This study provides a basis for a new and straightforward method for LC/MS/MS-based screening of N-terminal protein adducts. This procedure is denoted the "FIRE procedure" as fluorescein isothiocyanate (FITC) gave superior sensitivity by LC/MS/MS when measuring adducts (R) of electrophilic compounds with a modified Edman procedure. The principles of the FIRE-procedure are that adducts to N-term...

Tryptic peptides obtained from normal prothrombin have been compared with those obtained from prothrombin synthesized by cattle given the vitamin K antagonist dicumarol. Two peptides were found which contain vitamin K-dependent structures. These peptides contain residues 4 through 10 and residues 12 through 44, respectively. One of these (residues 4 through 10) has previously been shown to cont...

Tryptic peptides obtained from normal prothrombin have been compared with those obtained from prothrombin synthesized by cattle given the vitamin K antagonist dicumarol. Two peptides were found which contain vitamin K-dependent structures. These peptides contain residues 4 through 10 and residues 12 through 44, respectively. One of these (residues 4 through 10) has previously been shown to cont...

4-NN-Dimethylaminoazobenzene 4'-isothiocyanate was synthesized for the purpose of improving the ease and sensitivity of peptide sequence analysis. The method of 4-NN-dimethylaminoazobenzene 4'-isothiocyanate synthesis, the preparation of 24 4-NN-dimethylaminoazobenzene-4'-thiohydantoins of amino acids and their t.l.c. separation are described. All the thiohydantoins, except those of leucine and...

A novel manual method for protein-sequence analysis is described. Three peptides, the hexapeptide (Leu-TRP-Met-Arg-Phe-Ala), insulin A chain and glucagon were used to test this technique. Peptides (1 or 2 nmol) were hydrolysed with acid and their qualitative amino acid compositions were confirmed by reacting with 4-NN-dimethylaminoazobenzene-4'-sulphonylchloride and 4-NN-dimethylaminoazobenzene...