Correlation between the compact regions predicted by the Average Distance Map (ADM) and the biologically active sites in atrial natriuretic peptide

The prediction of the short-range compact regions of human atrial natriuretic peptide (a-hANP), one of the biologically active peptides, has been made by means of the Average Distance Map(ADM). We found out that the location of the predicted short-range compact regions is consistent with the structural units determined by the NMR analysis (Kobayashiet al., 1988). Furthermore, the short-range compact regions correspond well to the biologically active areas of atriopeptin (103–125)-amide (which is homologous peptide toa-hANP), detected by the glycine substitution technique (Konishiet al., 1987). The results suggest that a predicted short-range compact region can be regarded as a possible active site in a biologically active peptide.     

Dystrophin in rod spherules; submembranous dense regions facing bipolar cell processes

 It is known that the retina contains the protein dystrophin in the ribbon synapse, but the ultrastructural analysis is not yet fully elucidated. Our previous study reported that dystrophin is localized under the rod cell membranes in rat retinas. In the present study, we have investigated the relationship between dystrophin-rich regions of rod cell membranes and other neuronal processes in mouse retinas with a monoclonal antibody raised against the human dystrophin C-terminus. Immunoblotting, immunofluorescence stainings, and immunoelectron microscopy were employed. Immunoblotting analysis indicated that mouse retinas possessed some of the dystrophin isoforms of approximately 260 kDa, 140 kDa, and 70 kDa molecular weight. Confocal images showed a punctate appearance in the outer plexiform layer, as previously described. Immunoelectron microscopy showed that dystrophin immunoreactive products were always observed at submembranous dense regions of the rod spherule abutting bipolar processes. These results suggest that retinal dystrophin may be closely involved in signal transmission from rods to bipolar cells. Accepted: 7 May 1997     

The Incidence of R Factors in Bordetella bronchiseptica Isolated from Pigs

Bordetella bronchiseptica strains isolated from the nasal cavities of young pigs in Japan from 1969 to 1972 were surveyed for drug resistance and distribution of R factors. Of 304 strains examined, 71 (23%) were resistant to either one or more of following three drugs, streptomycin (SM), sulfadimethoxine (SA), and aminobenzyl penicillin (APC). Triple (SM.SA.APC)-resistance was most frequent among these resistant strains. Strains of double (SM. SA)- or single (SM)- and (SA)-resistance were also isolated, but were very few in numbers. Of the 71 drug-resistant strains, 61 (86%) were found to carry R factors which were capable of conjugal transfer. All of these R factors had the triple (SM.SA.APC)-resistant markers and were identified as fi^– (no fertility inhibition) type. The (SM.SA.APC)-resistant strains carrying R factors had been isolated from pigs reared on various farms in different districts, and consequently the prevalence of B. bronchiseptica strains carrying R factors was considered to be relatively wide-spread in young pigs.     

Gelation of Limulus Lysate by Synthetic Dextran Derivatives

The Limulus test has been considered specific for the presence of bacterial endotoxins. To synthesize a simple model of endotoxin, palmitoyldextran phosphate was prepared by modification of dextran by palmitoylation and phosphorylation. The present studies indicated that a variety of polysaccharide derivatives, such as palmitoyldextran phosphate, palmitoyldextran, and dextran phosphate, give a positive Limulus test and show pyrogenic activity, except for low molecular dextran derivatives. On the other hand, polysaccharides, such as dextran, starch (soluble), chitosan, xylan, and lentinan, were negative in these assays. The gelation reaction of Limulus lysate by modified dextran derivatives may depend on the molecular weight or modification of polysaccharides by palmitoylation and/or phosphorylation to a great extent.     

Improvement of Intracellular Traffic System by Overexpression of KDEL Receptor 1 in Antibody‐Producing CHO Cells

The localization of soluble endoplasmic reticulum (ER) chaperones in the cell organelle is mediated by the C‐terminal KDEL (lysine, aspartic acid, glutamic acid and leucine) motif. This motif is recognized by the KDEL receptor, a seven‐transmembrane protein that cycles between the ER and cis‐Golgi to capture missorted KDEL chaperones from post‐ER compartments in a pH‐dependent manner. The KDEL receptor's target chaperones have a substantial role in protein folding and assembly. In this study, the gene expression level of KDEL receptor 1 shows a moderate upregulation during either ER stress or growth of Chinese hamster ovary (CHO) cells in batch culture, while the ER chaperones show higher upregulation. This might indicate the possibility of saturation of the ER retention machinery or at least hindered retention during late stage batch culture in recombinant CHO cells. KDELR1 is overexpressed in a monoclonal antibody‐producing CHO cell line to improve the intracellular chaperone retention rate in the ER. An increase in the specific productivity of IgG1 by 13.2% during the exponential phase, and 23.8% in the deceleration phase of batch culture is observed. This is the first study to focus on the ER retention system as a cell engineering target for enhancing recombinant protein production.     

Dietary GABA induces endogenous synthesis of a novel imidazole peptide homocarnosine in mouse skeletal muscles

Amino Acids - Carnosine (β-alanyl-l-histidine) is an imidazole dipeptide present at high concentrations in skeletal muscles, where it plays a beneficial role. However, oral intake of carnosine...     

Partial silencing of fucosyltransferase 8 gene expression inhibits proliferation of Ishikawa cells,a cell line of endometrial cancer

Endometrial cancer is the most common gynecologic malignancy and is associated with increased morbidity each year, including young people. However, its mechanisms of proliferation and progression are not fully elucidated. It is well known that abnormal glycosylation is involved in oncogenesis, and fucosylation is one of the most important types of glycosylation. In particular, fucosyltransferase 8 (FUT8) is the only FUT responsible for α1, 6-linked fucosylation (core fucosylation), and it is involved in various physiological as well as pathophysiological processes, including cancer biology. Therefore, we aimed to identify the expression of FUT8 in endometrial endometrioid carcinoma and investigate the effect of the partial silencing of the FUT8 gene on the cell proliferation of Ishikawa cells, an epithelial-like endometrial cancer cell line. Quantitative real-time PCR analysis showed that FUT8 gene expression was significantly elevated in the endometrial endometrioid carcinoma, compared to the normal endometrium. The immunostaining of FUT8 and Ulex europaeus Agglutinin 1 (UEA-1), a kind of lectin family specifically binding to fucose, was detected endometrial endometrioid carcinoma. The proliferation assay showed FUT8 partial knockdown by transfection of siRNA significantly suppressed the proliferation of Ishikawa cells, concomitant with the upregulation in the gene expressions associated with the interesting pathways associated with de-ubiquitination, aspirin trigger, mesenchymal-epithelial transition (MET) et al. It was suggested that the core fucosylation brought about by FUT8 might be involved in the proliferation of endometrial endometrioid carcinoma cells.