Synthetic lipopeptide analogues of the N-terminus of bacterial lipoprotein are effective activators of macrophages, neutrophils and lymphocytes. We studied the effect of the lipopeptide N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]- (R)-cysteinyl-(S)-seryl-(S)-lysyl-(S)-lysyl-(S)-lysyl-(S)-lysine [Pam3Cys-Ser-(Lys)4] on tyrosine phosphorylation in dibutyryl-cyclic-AMP-differentiated HL-60 ...

4-Methylideneimidazole-5-one (MIO)-containing aminomutases catalyze the conversion of L-α-amino acids to β-amino acids with either an (R) or an (S) configuration. L-phenylalanine and L-tyrosine are the only two natural substrates identified to date. The enediyne chromophore of the chromoprotein antitumor antibiotic kedarcidin (KED) harbors an (R)-2-aza-3-chloro-β-tyrosine moiety reminiscent of ...

fms-like tyrosine kinase-3 is a receptor tyrosine kinase expressed by immature hematopoietic cells and is important for the normal development of stem cells and the immune system. mutations of fms-like tyrosine kinase-3 have been detected in about 30% of patients with acute myelogenous leukemia and a small number of patients with acute lymphoblastic leukemia. the fms-like tyrosine kinase-3 muta...

background: the hepatic secretion of apolipoprotein b (apob), containing lipoproteins, is known to be regulated by insulin, and the overproduction of these atherogenic lipoproteins occurs in insulin-resistant states. protein tyrosine phosphatase 1b (ptp-1b) is a key regulator of hepatic insulin signaling and is also upregulated in insulin resistance. we aimed to investigate the role of ptp-1b i...

protein tyrosine phosphatases (ptpases) regulate the tyrosine phosphorylation of target proteins in volved in several biological activities including cell proliferation and transformation. protein tyrosine phosphatase e (ptpe) contains duplicated ptpase-like domains and a short extracellular region. us ing the fluorescence in situ hybridization method, the gene encoding ptpe (locus symbol ptpre...

expression of receptor tyrosine kinase ror1 in a wide variety of cancers has emerged as a new era focusing on targeting this receptor in cancer therapy. our preliminary re-sults indicate the presence of a truncated transcript of ror1 in tumor cells. the trun-cated ror1 encompasses extracellular and transmembrane domains, lacking catalytic kinase domain (ror1-ecd). as enzyme activity is highly d...

We previously reported that a factor(s) from rat choriocarcinoma (Rcho-1) cells suppresses circulating PRL levels and increases tyrosine hydroxylase activity in tuberoinfundibular dopaminergic neurons in vivo. The purposes of this study were to determine whether this factor(s) increases tyrosine hydroxylase activity in fetal hypothalamic cells in vitro and to evaluate its chemical nature. The R...

The specificity (S) subunit of the restriction enzyme EcoKI imparts specificity for the sequence AAC(N6)GTGC. Substitution of thymine with bromodeoxyuridine in a 25 bp DNA duplex containing this sequence stimulated UV light-induced covalent crosslinking to the S subunit. Crosslinking occurred only at the residue complementary to the first adenine in the AAC sequence, demonstrating a close conta...

Oxidative coupling between tyrosine and tryptophan residues of peptides allows living organisms to produce highly intricate natural products. Their respective biosynthesis inspired synthetic chemists develop innovative strategies access these structurally challenging compounds. For more details see the Minireview by G. Vincent S. Tang on page 2612.