Sequences of cDNAs for human salivary and pancreatic α-amylases

The nucleotide sequences of the cloned human salivary and pancreatic α-amylase cDNAs correspond to the continuous mRNA sequences of 1768 and 1566 nucleotides, respectively. These include all of the amino acid coding regions. Salivary cDNA contains 200 bp in the 5′-noncoding region and 32 in the 3′-noncoding region. Pancreatic cDNA contains 3 and 27 bp of 5′- and 3′-noncoding regions, respectively. The nucleotide sequence humology of the two cDNAs is 96% in the coding region, and the predicted amino acid sequences are 94% homologous.Comparison of the sequences of human α-amylase cDNAs with those previously obtained for mouse α-amylase genes (Hagenbuchle et al., 1980; Schibler et al., 1982) showed the possibility of gene conversion between the two genes of human α-amylase.     

Catalytic function of a tyrosyl residue in tryptophanase

Tryptophanase has an essential tyrosyl residue/active site which can be modified by tetranitromethane. Pyridoxal 5'-phosphate can prevent this modification efficiently, whereas pyridoxal 5'-phosphate N-oxide cannot, indicating that the free pyridinium N is required for the interaction of the coenzyme with the tyrosyl residue, probably via a hydrogen bond. The weakened binding of the coenzyme to the modified enzyme was confirmed on gel filtration, the modified enzyme being dissociated from the coenzyme seven-fold faster than the native enzyme. Furthermore, absorption spectral analyses demonstrated that the modified enzyme can catalyze the transaldimination step, but fails to abstract the alpha-H of substrates. The tyrosyl residue, therefore, not only participates in coenzyme binding, but also contributes to alpha-H labilization.     

Prevalence rate and age of acquisition of antibodies against JC virus and BK virus in human sera

A total of 480 serum samples from donors including 384 children up to 10 years of age were examined by the hemagglutination-inhibition (HI) test for the rates of prevalence and age of acquisition of HI antibodies against JC virus and BK virus. Among 136 serum samples from various age groups, there were five (4%) with no detectable antibodies against BK or JC virus, 75 (55%) with antibodies against both viruses, 41 (30.1%) with antibodies against only BK virus and 26 (19%) with antibodies against only JC virus. The prevalence of antibodies against JC and BK viruses was 70.5% and 80.8%, respectively, and the mean HI titers (4 x 2n,n greater than or equal to 1) were 4.90 and 4.30. About 50% of the children had acquired antibodies against BK virus by 3 years of age and against JC virus by 6 years of age. These results indicate that dual latent infections with both viruses are common, although independent infections with either virus are predominant in the human population.     

Accuracy evaluation of sleep-wake stage analysis with SleepSign Ver2.0

Sleep and Biological Rhythms -     

4′,6-Dimethoxyisoflavone-7-<Emphasis Type="Italic">O</Emphasis>-β-<Emphasis Type="SmallCaps">d</Emphasis>-glucopyranoside (wistin) is a peroxisome proliferator-activated receptor α (PPARα) agonist in mouse hepatocytes

Human calcium/calmodulin-dependent protein kinase IV (CAMKIV) is a member of Ser/Thr kinase family, and is associated with different types of cancer and neurodegenerative diseases. Vanillin is a natural compound, a primary component of the extract of the vanilla bean which possesses varieties of pharmacological features including anti-oxidant, anti-inflammatory, anti-bacterial and anti-tumor. Here, we have investigated the binding mechanism and affinity of vanillin to the CAMKIV which is being considered as a potential drug target for cancer and neurodegenerative diseases. We found that vanillin binds strongly to the active site cavity of CAMKIV and stabilized by a large number of non-covalent interactions. We explored the utility of vanillin as anti-cancer agent and found that it inhibits the proliferation of human hepatocyte carcinoma (HepG2) and neuroblastoma (SH-SY5Y) cells in a dose-dependent manner. Furthermore, vanillin treatment resulted into the significant reduction in the mitochondrial membrane depolarization and ROS production that eventually leads to apoptosis in HepG2 and SH-SY5Y cancer cells. These findings may offer a novel therapeutic approach by targeting the CAMKIV using natural product and its derivative with a minimal side effect.     

Isolation of Crystalline Quinolinate Phosphoribosyltransferase from Alcaligenes eutrophus nov. subsp. quinoiinicus and Its Behavior on Polyacrylamide Gel Disc Electrophoresis

Quinolinate phosphoribosyltransferase (EC 2.4.2.19) was purified and crystallized from cell-free extracts of Alcaligenes eutrophus nov. subsp. quinoiinicus, IAM 12305 which was isolated in our laboratory from soil. The enzyme was labile in the cold, and all purification steps were performed at room temperature (10~15°C). The crystalline enzyme was certified to be homogeneous by ultracentrifugal analysis and starch-gel electrophoresis. On polyacrylamide gel disc electrophoresis, the crystalline enzyme showed a multiple profile, but it showed a single band by addition of a certain amount of glycerol and 2-mercaptoethanol. The adding effect of these compounds was discussed.