Manzamenones L–N,new dimeric fatty-acid derivatives from an Okinawan marine sponge Plakortis sp.

Three new polyketides, manzamenones L–N (1–3), have been isolated from an Okinawan marine sponge of the genus Plakortis. The structures of 1–3 were elucidated on the basis of spectroscopic data. Manzamenones L–N (1–3) were new dimeric fatty-acid derivatives consisting of a tetrahydroindenone with three carboxy groups and two hexadecanyl chains. Manzamenones M (2) and N (3) showed antimicrobial activity against several bacteria and fungi.     

Identification of N-substituted 8-azatetrahydroquinolone derivatives as selective and orally active M1 and M4 muscarinic acetylcholine receptors agonists

We designed and synthesized N-substituted 8-azatetrahydroquinolone derivatives as selective M₁ and M₄ muscarinic acetylcholine receptors agonists. Optimization of selected derivatives led to the discovery of compound 7 as a highly potent M₁ and M₄ agonist with weak hERG inhibition. Oral administration of compound 7 improved psychosis-like behavior in rats.     

Inhibitory effects of metachromins L–Q and its related analogs against receptor tyrosine kinases EGFR and HER2

Metachromins are a series of sesquiterpenoid quinones isolated from Okinawan marine sponges. Inhibitory effects of metachromins L–Q (1–6), sesquiterpenoid quinones with an amino acid residue, and their related analogs (7–18) prepared from metachromins A (19) and C (20) against receptor tyrosine kinases EGFR and HER2 were investigated. Two analogs 11 and 12 showed relatively stronger inhibitory activity against EGFR, while metachromins L–Q (1-6) and seven analogs (8, 10, 11, and 15–18) showed inhibitory activities against HER2.     

Physicochemical Parameters for Structure-Activity-Studies of Substituted Phenyl N-Methylcarbamates

The electronic and hydrophobic substituent parameters of a number of o-, m- and p- substituted phenyl N-methylcarbamates were estimated by measuring the alkaline catalyzed hydrolysis rate constant and 1-octanol/water partition coefficient. Since some o-substituted derivatives are very potent insecticides, emphasis was placed on determining the ortho substituent effects in terms of the existing free-energy related parameters. The information obtained should be useful in structure-activity studies of carbamate insecticides.     

The Nutritional Value of D-Amino Acid in the Chick Nutrition

The nutritional values of 16 D-amino acids in chick growth were studied on the purified diets containing crystalline amino acids as a sole source of nitrogen. Growth rate, feed consumption and nitrogen retention were measured. The nutritional values of D-amino acids were studied by comparing individually with the control groups fed on the diet containing all L-amino acids and negative control groups fed with the diet omitted the corresponding L-isomer. The following results were obtained. Essential amino acids: 1. Equal or almost equal nutritional value to the corresponding L-isomer; methionine, phenylalanine, leucine, proline. 2. Half nutritional value compared with L-isomer; valine. 3. Small nutritional value compared with L-isomer; tryptophan, isoleucine, histidine. 4. No nutritional value; lysine, threonine, arginine. Non-essential amino acid: 1. Equal or almost equal nutritional value to the corresponding L-isomer; serine, tyrosine, cystine. 2. There is a possibility that it has a slight growth retardation effect; alanine. 3. The growth retardation effect was found; aspartic acid.     

Spatial arrangement of proteins using scCro-tag: application for an in situ enzymatic microbead assay

ABSTRACT

In natural systems, various metabolic reactions are often spatially organized to increase enzyme activity and specificity. Thus, by spatially arranging enzyme molecules in synthetic systems to imitate these natural systems, it is possible to promote a high rate of enzymatic turnover. In this present study, a normal and mutant form of the scCro DNA-binding protein were shown to bind orthogonally to specific recognition sequences under appropriate conditions. Furthermore, these DNA-binding tags were used to establish an enzyme assay system based on the spatial arrangement of transglutaminase and its substrate at the molecular level. Together, the results of the present study suggest that the scCro-tag may be a powerful tool to facilitate the synthetic spatial arrangement of proteins on a DNA ligand.     

miR-146a Polymorphism (rs2910164) Predicts Colorectal Cancer Patients’ Susceptibility to Liver Metastasis

miR-146a plays important roles in cancer as it directly targets NUMB, an inhibitor of Notch signaling. miR-146a is reportedly regulated by a G>C polymorphism (SNP; rs2910164). This polymorphism affects various cancers, including colorectal cancer (CRC). However, the clinical significance of miR-146a polymorphism in CRC remains unclear. A total of 59 patients with CRC were divided into 2 groups: a CC/CG genotype (n = 32) and a GG genotype (n = 27), based on the miR-146a polymorphism. cDNA microarray analysis was performed using 59 clinical samples. Significantly enriched gene sets in each genotype were extracted using GSEA. We also investigated the association between miR-146a polymorphism and miR-146a, NUMB expression or migratory response in CRC cell lines. The CC/CG genotype was associated with significantly more synchronous liver metastasis (p = 0.007). A heat map of the two genotypes showed that the expression profiles were clearly stratified. GSEA indicated that Notch signaling and JAK/STAT3 signaling were significantly associated with the CC/CG genotype (p = 0.004 and p = 0.023, respectively). CRC cell lines with the pre-miR-146a/C revealed significantly higher miR-146a expression (p = 0.034) and higher NUMB expression and chemotactic activity. In CRC, miR-146a polymorphism is involved in liver metastasis. Identification of this polymorphism could be useful to identify patients with a high risk of liver metastasis in CRC.     

Nucleosomal arrays self‐assemble into supramolecular globular structures lacking 30‐nm fibers

The existence of a 30‐nm fiber as a basic folding unit for DNA packaging has remained a topic of active discussion. Here, we characterize the supramolecular structures formed by reversible Mg²⁺‐dependent self‐association of linear 12‐mer nucleosomal arrays using microscopy and physicochemical approaches. These reconstituted chromatin structures, which we call “oligomers”, are globular throughout all stages of cooperative assembly and range in size from ~50 nm to a maximum diameter of ~1,000 nm. The nucleosomal arrays were packaged within the oligomers as interdigitated 10‐nm fibers, rather than folded 30‐nm structures. Linker DNA was freely accessible to micrococcal nuclease, although the oligomers remained partially intact after linker DNA digestion. The organization of chromosomal fibers in human nuclei in situ was stabilized by 1 mM MgCl₂, but became disrupted in the absence of MgCl₂, conditions that also dissociated the oligomers in vitro. These results indicate that a 10‐nm array of nucleosomes has the intrinsic ability to self‐assemble into large chromatin globules stabilized by nucleosome–nucleosome interactions, and suggest that the oligomers are a good in vitro model for investigating the structure and organization of interphase chromosomes.     

Purification and some properties of ornithine decarboxylase from rat liver

Ornithine decarboxylase (EC 4.1.1.17) was purified to near homogeniety from livers of thioacetamide- and dl-α-hydrazino-δ-aminovaleric acid-treated rats by using three types of affinity chromatography with pyridoxamine phosphate-Sepharose, pyridoxamine phosphate-dipropylenetriamine-Sepharose and heparin-Sepharose. This procedure gave a purification of about 3.5·10⁵-fold with an 8% yield; the specific activity of the final enzyme preparation was 1,1·10⁶ nmol CO₂/h per mg protein. The purified enzyme gave a single band of protein which coincided with activity peak on polyacrylamide gel electrophoresis and also gave a single major band on SDS-polyacrylamide gel electrophoresis. A single precipitin line was formed between the purified enzyme and an antiserum raised against a partially purified enzyme, on Ouchterlony immunodiffusion. The molecular weight of the enzyme was estimated to be 105 000 by polyacrylamide gel electrophoresis at several different gel concentrations; the dissociated subunits had molecular weights of 50 000 on SDS-polyacrylmide gels. The isoelectric point of the enzyme was pH 4.1.