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Growth-blocking peptide (GBP) is a 25-amino acid insect cytokine found in Lepidopteran insects that possesses diverse biological activities such as larval growth regulation, cell proliferation, and stimulation of immune cells (plasmatocytes). The tertiary structure of GBP consists of a structured core that contains a disulfide bridge and a short antiparallel beta-sheet (Tyr(11)-Arg(13) and Cys(19)-Pro(21)) and flexible N and C termini (Glu(1)-Gly(6) and Phe(23)-Gln(25)). In this study, deletion and point mutation analogs of GBP were synthesized to investigate the relationship between the structure of GBP and its mitogenic and plasmatocyte spreading activity. The results indicated that deletion of the N-terminal residue, Glu(1), eliminated all plasmatocyte spreading activity but did not reduce mitogenic activity. In contrast, deletion of Phe(23) along with the remainder of the C terminus destroyed all mitogenic activity but only slightly reduced plasmatocyte spreading activity. Therefore, the minimal structure of GBP containing mitogenic activity is 2-23 GBP, whereas that with plasmatocyte spreading activity is 1-22 GBP. NMR analysis indicated that these N- and C-terminal deletion mutants retained a similar core structure to wild-type GBP. Replacement of Asp(16) with either a Glu, Leu, or Asn residue similarly did not alter the core structure of GBP. However, these mutants had no mitogenic activity, although they retained about 50% of their plasmatocyte spreading activity. We conclude that specific residues in the unstructured and structured domains of GBP differentially affect the biological activities of GBP, which suggests the possibility that multifunctional properties of this peptide may be mediated by different forms of a GBP receptor.

The flow of a film under a plate is investigated. An expression is obtained for determining the angle of inclination of the plate, for large values of which the flow of the film transforms into wave motion.

Three kinds of ²H-labeled Bombyx mori silk fibroin samples (with [2,2-²H2]Gly, [3,3,3-²H3]Ala, or [2,3,5,6-²H4]Tyr) were obtained by oral administration of either the labeled amino acid or ²H2O to 5th instar larvae. The administration of ²H2O alone yielded a high degree of selective deuteration at the alanine methyl group, since the incorporation of ²H2O occurs between fumarate and malate in the tricarboxylic acid (TCA) cycle of the silk fibroin synthetic pathway. Uniaxially oriented silk fibers were prepared as samples for ²H-NMR spectroscopy. An analysis of the quadrupole echo line shape was carried out in order to determine the angle of the deuterium-labeled group relative to the fiber axis, i.e., of the Cα−²H bond vectors in glycine and of Cα−Cβ²H3 in alanine. With the fiber axis aligned parallel to the magnetic field, quadrupole splittings were obtained as 117.8 and 39.8 kHz for [2,2-²H2]Gly- and [3,3,3-²H3]Ala-labeled silk, respectively. These values are identical with those obtained from the ²H-NMR powder patterns of the unaligned samples, within experimental error. From the angular dependence of the quadrupole splittings, it was thus calculated that the Cα−²H bonds of glycine as well as the Cα−Cβ²H3 bond of alanine make an angle of approximately 90° relative to the fiber axis. These steric constraints were then used to evaluate the torsion angles, φ and ψ, for the glycine and alanine residues within the protein backbone. These data, determined independently by solid-state ²H NMR, thus verified and narrowed down the allowed region in the Ramachandran (φ, ψ) map obtained from previous solid-state ¹³C- and ¹⁵N-NMR studies.

We discovered that an amorphous-crystalline transition occurs when a small amount of water is introduced into an amphiphilic copolymer network consisting of n-alkyl acrylate (n = 14, 16, 18, 20, 22) and acrylic acid. Differential scanning calorimetry and X-ray diffraction studies show that the dry polymer network is in an amorphous state regardless of the presence of the crystalline moiety. By introduction of water to the polymer network, a crystalline structure attributed to the side-by-side packing of the alkyl chain is formed and the melting temperature of the crystalline increases with the amount of water and saturated to that of homo-n-alkyl acrylate polymers at a water content of 5 wt %. The mechanism of the water-induced amorphous-crystalline transition is explained in terms of enhanced mobility of the main chain due to hydration of the carboxyl groups of the polymer network.

Primary aldosteronism (PA) is mainly caused by aldosterone producing adenoma and idiopathic bilateral adrenal hyperplasia (IHA). Laparoscopicadrenalectomy is recommended for the treatment of APA. Medical treatment with a mineralocorticoid receptor (MR) antagonist such as spironolactone (SP) or eplerenone(EP) is recommended for patients with IHA. Fishcher et al reported that the prevalence of spontaneous remission of IHA during long-term treatment with SP was 5.4 (Clin Endocrinol 2011). We aimed to determine the prevalence of spontaneous remission of PA during long-term treatment with MR antagonists (SP or EP) in Japan.

Adrenal vein sampling (AVS) after ACTH stimulation is recommended for identifying the primary aldosteronism subtypes in Japan, but the cutoff values for ascertaining lateralization of aldosterone secretion remain controversial.