Small molecular CD4 mimics as HIV entry inhibitors

Derivatives of CD4 mimics were designed and synthesized to interact with the conserved residues of the Phe43 cavity in gp120 to investigate their anti-HIV activity, cytotoxicity, and CD4 mimicry effects on conformational changes of gp120. Significant potency gains were made by installation of bulky hydrophobic groups into the piperidine moiety, resulting in discovery of a potent compound with a higher selective index and CD4 mimicry. The current study identified a novel lead compound 11 with significant anti-HIV activity and lower cytotoxicity than those of known CD4 mimics.     

Fluorescent-responsive synthetic C1b domains of protein kinase Cδ as reporters of specific high-affinity ligand binding

Protein kinase C (PKC) is a critical cell signaling pathway involved in many disorders such as cancer and Alzheimer-type dementia. To date, evaluation of PKC ligand binding affinity has been performed by competitive studies against radiolabeled probes that are problematic for high-throughput screening. In the present study, we have developed a fluorescent-based binding assay system for identifying ligands that target the PKC ligand binding domain (C1 domain). An environmentally sensitive fluorescent dye (solvatochromic fluorophore), which has been used in multiple applications to assess protein-binding interactions, was inserted in proximity to the binding pocket of a novel PKCδ C1b domain. These resultant fluorescent-labeled δC1b domain analogues underwent a significant change in fluorescent intensity upon ligand binding, and we further demonstrate that the fluorescent δC1b domain analogues can be used to evaluate ligand binding affinity.     

Monitoring of environmental arsenic by cultures of the photosynthetic bacterial sensor illuminated with a near-infrared light emitting diode array

Recombinant Rhodopseudomonas palustris, harboring the carotenoid-metabolizing gene crtI (CrtIBS), and whose color changes from greenish yellow to red in response to inorganic As(III), was cultured in transparent microplate wells illuminated with a light emitting diode (LED) array. The cells were seen to grow better under near-infrared light, when compared with cells illuminated with blue or green LEDs. The absorbance ratio of 525 to 425 nm after cultivation for 24 h, which reflects red carotenoid accumulation, increased with an increase in As(III) concentrations. The detection limit of cultures illuminated with near-infrared LED was 5 microgram/l, which was equivalent to that of cultures in test tubes illuminated with an incandescent lamp. A near-infrared LED array, in combination with a microplate, enabled the simultaneous handling of multiple cultures, including CrtIBS and a control strain, for normalization by the illumination of those with equal photon flux densities. Thus, the introduction of a near-infrared LED array to the assay is advantageous for the monitoring of arsenic in natural water samples that may contain a number of unknown factors and, therefore, need normalization of the reporter event.     

A wheat homolog of MOTHER OF FT AND TFL1 acts in the regulation of germination

Seed dormancy is an adaptive mechanism and an important agronomic trait. Temperature during seed development strongly affects seed dormancy in wheat (Triticum aestivum) with lower temperatures producing higher levels of seed dormancy. To identify genes important for seed dormancy, we used a wheat microarray to analyze gene expression in embryos from mature seeds grown at lower and higher temperatures. We found that a wheat homolog of MOTHER OF FT AND TFL1 (MFT) was upregulated after physiological maturity in dormant seeds grown at the lower temperature. In situ hybridization analysis indicated that MFT was exclusively expressed in the scutellum and coleorhiza. Mapping analysis showed that MFT on chromosome 3A (MFT-3A) colocalized with the seed dormancy quantitative trait locus (QTL) QPhs.ocs-3A.1. MFT-3A expression levels in a dormant cultivar used for the detection of the QTL were higher after physiological maturity; this increased expression correlated with a single nucleotide polymorphism in the promoter region. In a complementation analysis, high levels of MFT expression were correlated with a low germination index in T1 seeds. Furthermore, precocious germination of isolated immature embryos was suppressed by transient introduction of MFT driven by the maize (Zea mays) ubiquitin promoter. Taken together, these results suggest that MFT plays an important role in the regulation of germination in wheat.     

N-glycans from porcine trachea and lung: predominant NeuAcα2-6Gal could be a selective pressure for influenza variants in favor of human-type receptor

It is known that pigs acted as "mixing vessels" for genesis of a new reassortant influenza strain responsible for pandemic H1N1 2009. However, the host factors driving the evolution of a reassorted virus in pigs to 'jump species' resulting in a human outbreak remain unclear. N-glycans derived from the porcine respiratory tract were enzymatically released, fluorescent labeled with 2-aminopyridine, separated according to charge, size and hydrophobicity, and structurally identified by a two-dimensional (size and hydrophobicity) HPLC mapping technique and MALDI-TOF mass spectrometry before and after exo-glycosidase digestion. We found a 3-, 5-, and 13-fold increases in NeuAcα2-6, a preferable human influenza receptor, over NeuAcα2-3, an avian influenza receptor, from upper and lower parts of the porcine trachea towards the porcine lung, a major target organ for swine virus replication. The large proportion of NeuAcα2-6 may exert selective pressure for selection of influenza variants with altered receptor preference for this human-type α2-6 receptor, a crucial first step for generating a human pandemic.     

Secernin-1 as a novel prognostic biomarker candidate of synovial sarcoma revealed by proteomics

We aimed to develop prognostic biomarkers for synovial sarcoma employing a proteomic approach. We examined the proteomic profile of synovial sarcoma using two-dimensional difference gel electrophoresis (2D-DIGE). We identified 20 protein spots whose intensity was statistically different (p<0.01) between a group of eight patients who were alive and continuously disease-free for over five years and a group of five patients who died of the disease within two years post diagnosis. Mass spectrometric protein identification demonstrated that these 20 spots corresponded to 17 distinct gene products. Three of the 20 spots corresponded to secernin-1 and had higher intensity in the good prognosis group. The prognostic performance of secernin-1 was further examined immunohistochemically in 45 synovial sarcoma cases. The 5-year survival rate was 77.6% and 21.8% for patients with secernin-1 positive and negative primary tumors respectively (p=0.0015). The metastasis-free survival was significantly higher in the patient group with high secernin-1 expression compared to that with low expression (p=0.0012). Uni- and multivariate analyses revealed that secernin-1 expression was a powerful prognostic factor compared to other clinico-pathological parameters examined. These results indicate that secernin-1 may be used as a biomarker to predict the overall and metastasis-free survival in synovial sarcoma patients.     

Selenoureas and thioureas are effective superoxide radical scavengers in vitro

Oxygen radicals, such as superoxide radicals, embellishing DNA, protein, lipids, etc., and carrying out the obstacle of the function of a cell is known. It depends for the oxidant level in the living body on the balance of a generation system and an elimination system of oxygen radicals, and research which controls an oxidant level in the living body is briskly done by taking in the substance which eliminates an oxygen radical. We investigated scavenging effects of superoxide radicals by selenoureas and thioureas using a highly sensitive and quantitative chemiluminescence method. At 330 nM, five selenoureas and five thioureas scavenged fractions of superoxide radicals (O2-) ranging from 8.4% to 87.6%. Among five N,N-unsubstituted selenoureas and N,N-unsubstituted thioureas 1-selenocarbamoylpiperidine and 1-thiocarbamoylpyrrolidine were the most effective scavengers. A possibility that selenoureas could use it as a new superoxide anion-scavenging substance from the result of this research became clear.     

A comparison of interval mapping procedures including the QTL-cluster mapping

Using the deterministic sampling, patterns of the log-likelihood surfaces expected in some interval mapping procedures for estimating the position of, and the effect for, QTL(s) were investigated for the situations where a single QTL or closely linked QTLs are contained in a chromosome segment bracketed with two markers. The mapping procedures compared were the conventional, likelihood-based interval mapping (IM), the regression interval mapping (RIM), and the QTL-cluster mapping (CM) in which the conditional probabilities of transmission of the whole segment marked by the flanking markers were taken into consideration. The half-sib design was used here, and several cases of the true genetic model were considered, differing in the number of QTLs contained in the marker interval, the linkage phase for the sire, and the magnitude of the QTL(s) effect. For the true genetic models where a single QTL or closely linked QTLs being in coupling phase are contained in the interval, with (R)IM, clear global maxima of the log-likelihood were observed within the range of the marker interval. It was shown that the estimates of the QTL(s) effect at the marked segment level are expected to be unbiased. On the other hand, in a setting where the linkage phase for the linked QTLs located in the interval was different from coupling and repulsion, there was found a ridge along the interval for the log-likelihood surface with (R)IM, indicating the dependency between the estimates of the position of, and the effect for, the putative QTL. For this case, it was found that the position of the putative QTL could be estimated as that of one of the flanking markers, and the estimate of the QTL effect be biased. In contrast, it was revealed that CM is expected to provide the unbiased estimate of the QTL(s)-effect at the segment level for any case of the true genetic models considered here. If the aim is for marker-assisted selection rather than mapping closely linked QTLs individually, then the CM approach is considered to be useful.