Structure-activity relationship of neuropeptide gamma derived from mammalian and fish.

This study of relationship between structure and biologic activity was performed using five neuropeptide gammas [NPgamma; mammalian-NPgamma (M-NPgamma), trout-NPgamma (T-NPgamma), goldfish-NPgamma (G-NPgamma), bowfin-NPgamma (B-NPgamma), and shark-NPgamma (S-NPgamma)]. Circular dichroism (CD) spectra showed that all peptides took random structure in buffer solution. In neutral and acidic liposomes, M-NPgamma, T-NPgamma, B-NPgamma, and S-NPgamma still adopted random structure, while G-NPgamma had an alpha-helical structure. The biologic activity of NPgammas has been estimated by their effects on the intestinal motility and arterial relaxation. The intestinal motility was investigated with rat duodenum (RD), carp intestine (CI), and guinea-pig ileum (GPI). The arterial relaxing effect was tested with guinea-pig aorta (GPA) and rat mesenteric artery (RMA). In RD, the order of potency compared with the EC50 value was M-NPgamma > S-NPgamma > B-NPgamma > G-NPgamma > T-NPgamma. G-NPgamma was the most contractile agent in CI. S-NPgamma was the most contractile agent in GPI. Using an arterial relaxing test, the order of potency was G-NPgamma > T-NPgamma > B-NPgamma > S-NPgamma > M-NPgamma in GPA, and all NPgammas remarkably reduced relaxing activity in RMA. Despite their structural similarities to NPgammas, G-NPgamma has high affinity to tachykinin receptor-binding sites in GPA and CI, indicating an alpha-helical structure may have a critical role for receptor binding. However, an alpha-helical structure does not play a critical role in recognizing receptor-binding sites in RD and GPI.     

Modulation of catalase in human skin in vivo by acute and chronic UV radiation.

In this study, we demonstrate that catalase is differently regulated either by acute, or chronic UV radiation during the photoaging process. 2MED of UV radiation decreased the activity and expression of catalase gradually in the epidermis and dermis at between 24 and 48 h after the UV exposure. These levels then returned to near normal by 72 h after exposure. The catalase mRNA was also decreased in the skin 24 h after UV irradiation to 50% of the control level, and then started to recover. In contrast, chronic UV irradiation over a lifetime (approximately 50 years) increased the catalase activity in the epidermis and dermis of the human skin in vivo. Our results suggest that catalase might be one of the important enzymes in the skin aging process, and that it plays an important role in the photoprotection of the skin from UV light.     

Plant defense gene promoter enhances the reliability of<Emphasis Type="Italic"> shiva-1</Emphasis> gene-induced resistance to soft rot disease in potato

PAL5, a tomato (Lycopersicon esculentum Mill.) plant defense gene that encodes phenylalanine ammonia-lyase, is known to respond to a variety of environmental stresses including pathogen infection and wounding. A shiva-1 gene recombinant that encodes a small synthetic antibacterial peptide under the PAL5 gene promoter was transformed into potato (Solanum tuberosum L.) and its ability to induce resistance to Erwinia carotovora was compared with a construct under the control of the constitutive and widely used cauliflower mosaic virus (CaMV) 35S promoter. The shiva-1 peptide, an analog of natural cecropin B, was shown previously to have high bactericidal activity in vitro, but when expressed in vivo under the control of the CaMV 35S promoter, the effects were very inconsistent. As observed previously, in the present studies a few transformants with the CaMV 35S promoter were highly resistant when assayed for susceptibility to soft rot disease. In marked contrast the majority of transformants with the PAL5 gene promoter were highly resistant. More-detailed analyses of the incorporated DNA indicated that most of the transformants with the CaMV 35S promoter contained multiple copies of the transforming DNA while all of the PAL5 recombinants contained single copies. The highly resistant CaMV 35S recombinant also was present as a single copy. The results indicate that, at least in this instance, a constitutive promoter may not be ideal for the effective expression of a foreign gene and suggest that multiple insertions may have negative consequences.     

Structural basis for the selective inhibition of JNK1 by the scaffolding protein JIP1 and SP600125

The c-jun N-terminal kinase (JNK) signaling pathway is regulated by JNK-interacting protein-1 (JIP1), which is a scaffolding protein assembling the components of the JNK cascade. Overexpression of JIP1 deactivates the JNK pathway selectively by cytoplasmic retention of JNK and thereby inhibits gene expression mediated by JNK, which occurs in the nucleus. Here, we report the crystal structure of human JNK1 complexed with pepJIP1, the peptide fragment of JIP1, revealing its selectivity for JNK1 over other MAPKs and the allosteric inhibition mechanism. The van der Waals contacts by the three residues (Pro157, Leu160, and Leu162) of pepJIP1 and the hydrogen bonding between Glu329 of JNK1 and Arg156 of pepJIP1 are critical for the selective binding. Binding of the peptide also induces a hinge motion between the N- and C-terminal domains of JNK1 and distorts the ATP-binding cleft, reducing the affinity of the kinase for ATP. In addition, we also determined the ternary complex structure of pepJIP1-bound JNK1 complexed with SP600125, an ATP-competitive inhibitor of JNK, providing the basis for the JNK specificity of the compound.     

Production of high molecular weight pullulan by Aureobasidium pullulans HP-2001 with soybean pomace as a nitrogen source

The production of pullulan by Aureobasidium pullulans HP-2001 was enhanced by yeast extract as a nitrogen source as well as soybean pomace. The highest production of pullulan by A. pullulans HP-2001 with yeast extract was 5.5 g/l whereas that of pullulan with soybean pomace was 7.5 g/l. The gas chromatogram of pullulan produced by A. pullulans HP-2001 with soybean pomace as a nitrogen source showed that the major and minor components were glucose and mannose. The FTIR spectra of pullulans produced with yeast extract, a mixture of yeast extract and soybean pomace, and soybean pomace alone exhibited similar features. The increase in content of reducing sugars after pullulanase treatment of pullulans produced with different nitrogen sources indicated that all the pullulans had alpha-(1,6) glucosidic linkages of alpha-(1,4) linked maltotriose units. The average molecular weights of pullulans produced with various concentrations of yeast extract and soybean pomace ranged from 0.17 to 1.32x10(6) and from 1.32 to 5.66x10(6), respectively. All pullulans produced by A. pullulans HP-2001 in this study had the same basic structures, but their ratios of monomeric components were a little different, which might result in the production of pullulans with different molecular weights.     

Syntheses and anti-MRSA activities of the C3 analogs of mansonone F, a potent anti-bacterial sesquiterpenoid: insights into its structural requirements for anti-MRSA activity

Syntheses and excellent anti-MRSA activities of the mansonone F analogs are reported. In addition, the minimal structural requirements for its anti-MRSA activities as well as its structure-activity relationship including the C3 substituents effects on anti-MRSA activity are also described. In particular, this study revealed that both ortho-quinone and tricyclic systems of mansonone F are essential for anti-MRSA activities.     

Syntheses and radical scavenging activities of resveratrol derivatives

Nine new resveratrol derivatives, having bromo, iodo, and fluoroethyl groups, were designed and synthesized. All compounds having free phenol groups showed good free radical scavenging activity. Among them, 2-bromoresveratrol 19 has a similar free radical scavenging activity to (+)-catechin.     

Hypervariable and Highly Divergent Intron–Exon Organizations in the Chordate Oikopleura dioica

Oikopleura dioica is a pelagic tunicate with a very small genome and a very short life cycle. In order to investigate the intron–exon organizations in Oikopleura, we have isolated and characterized ribosomal protein EF-1, Hox, and -tubulin genes. Their intron positions have been compared with those of the same genes from various invertebrates and vertebrates, including four species with entirely sequenced genomes. Oikopleura genes, like Caenorhabditis genes, have introns at a large number of nonconserved positions, which must originate from late insertions or intron sliding of ancient insertions. Both species exhibit hypervariable intron–exon organization within their -tubulin gene family. This is due to localization of most nonconserved intron positions in single members of this gene family. The hypervariability and divergence of intron positions in Oikopleura and Caenorhabditis may be related to the predominance of short introns, the processing of which is not very dependent upon the exonic environment compared to large introns. Also, both species have an undermethylated genome, and the control of methylation-induced point mutations imposes a control on exon size, at least in vertebrate genes. That introns placed at such variable positions in Oikopleura or C. elegans may serve a specific purpose is not easy to infer from our current knowledge and hypotheses on intron functions. We propose that new introns are retained in species with very short life cycles, because illegitimate exchanges including gene conversion are repressed. We also speculate that introns placed at gene-specific positions may contribute to suppressing these exchanges and thereby favor their own persistence.Supplementary material () is available for this article.     

The influence of N-glycosylation and C-terminal sequence on secretion of HBV large surface antigen from S. cerevisiae

In Saccharomyces cerevisiae, we synthesized and secreted L-HBVsAg (named as pre-S(Met1 to Asn174)::S(Met175 to Ile400)) and three mutants, i.e., pre-S degree degree::S (Asn15Gln and Asn123Gln), pre-S degree degree::S degree (Asn15Gln, Asn123Gln, and Asn320Gln), and pre-S degree degree::S degree degree (Asn15Gln, Asn123Gln, Asn233Gln, and Asn320Gln). All of the secreted pre-S::S was N-glycosylated, i.e., hyper-mannosylated. In the secretion of pre-S degree degree::S and pre-S degree degree::S degree, besides the hyper-mannosylated form, another immunoreactive protein with much lower molecular mass was observed, which seems to be unglycosylated form of pre-S degree degree::S and pre-S degree degree::S degree. Only a part of the secreted pre-S degree degree::S or pre-S degree degree::S degree molecules was N-glycosylated, and the site for the partial N-glycosylation seems to be Asn233 in S-antigen region. Compared to the N-glycosylated pre-S degree degree::S and pre-S degree degree::S degree, pre-S degree degree::S degree degree (non-N-glycosylated mutant) was secreted with lower secretion efficiency but showed apparent immunoreactivity to anti-S antigen monoclonal Ab. Interestingly, unlike pre-S degree degree::S degree degree with authentic C-terminus, the recombinant pre-S degree degree::S degree degree with C-terminal myc or poly-histidine tag (pre-S degree degree::S degree degree::tag) was almost all aggregated into insoluble proteins in the intracellular region. Conclusively, the C-terminal sequence and glycosylation in S-antigen region seem to be of crucial importance in determining the secretion efficiency of L-HBVsAg in S. cerevisiae.