Peptide synthesis by surfactant-chymotrypsin complexes in organic media

Peptide synthesis by surfactant-chymotrypsin (CT) complexes was performed in organic media containing 1%–8% (v/v) water. The CT complex exhibited a higher enzymatic activity than native CT. The control of the water content in the reaction media has a crucial effect on the enzymatic activity. The maximum conversion (57%) for the peptide synthesis by the surfactant-CT complex was obtained at 4% water content.     

Tumor microenvironment disparity in multiple primary lung cancers: Impact of non-intrinsic factors,histological subtypes,and genetic aberrations

IntroductionMultiple primary lung cancers (MPLCs) occur in common carcinogenetic risks such as lifestyle, biological aging, immune responses, hormones, and metabolism. Although MPLCs harbor various genetic profiles within the same individuals, differences in the tumor microenvironment (TME) are unclear. We investigated the impact of genetic aberrations, non-intrinsic factors, and pathological subtypes on tumor immunity.Materials and MethodsIn total, 73 surgically resected specimens from 32 patients with MPLC were analyzed. PD-L1 expression in tumor cells (TCs) and immune cells (ICs), CD3-positive tumor-infiltrating lymphocytes (TILs), CD8/CD3 ratios, and FOXP3-positive TILs that compose TMEs were evaluated by immunohistochemistry and classified on a score of 0–2. 38 tumors were sequenced for somatic mutations in 409 cancer-associated genes.ResultsFemales and never or light smokers had a higher incidence of PD-L1-negative tumors and a higher concordance rate. PD-L1 positivity in TCs and ICs was significantly less frequent in EGFR-mutated than in wild-type tumors. Differences in the score of TMEs were observed between the KRAS-mutated-only tumor and the KRAS and TP53-co-mutated tumors, and between the KRAS-mutated-only tumor and the KRAS and STK11-co-mutated tumors. Significantly more FOXP3-high TILs were observed in invasive pathological subtypes than in non-invasive ones.ConclusionComparing TMEs among MPLCs revealed that non-smokers or light smokers and females were unlikely to express PD-L1 regardless of tumor site and confirmed that the EGFR mutations and co-occurring KRAS and STK11 or TP53 mutations were associated with TME. Pathological subtypes may impact the efficacy of immune therapy due to their potential correlations with regulatory T cells.     

Gelled Double-Layered Emulsions for Protection of Flaxseed Oil

Multilayer systems may present different functional properties according to the number of layers deposited, the type of biopolymers, the sequence of biopolymer layers, and the solution properties used during deposition. In this study, gelatin-stabilized emulsions were coated with alginate in order to produce double-layered emulsions. Concentrations of both primary emulsion and alginate in the outer layer were evaluated by a stability map. Results indicated the occurrence of depletion flocculation in emulsions with lower gelatin concentration due to excess of alginate. Stable emulsions were atomized in a calcium chloride solution for producing microgels, which resulted in semi-rounded monomodal particles. Emulsification process promoted a reduction in the content of the secondary oxidation products of flaxseed oil as compared to non-emulsified oil, while the gelation process was responsible for a considerable improvement on oxidative stability with significant reduction on both primary and secondary oxidation products during storage. These lipid-based microgels could be potentially used as delivery systems with improved oxidative stability.     

Development of novel PCR primer sets for DNA barcoding of aquatic insects,and the discovery of some cryptic species

Limnology - DNA barcoding is a powerful tool that provides rapid, accurate, and automatable species identification using standardized genetic region(s), such as for revealing the existence of...     

The Role of K<Superscript>+</Superscript>-Cl<Superscript>−</Superscript>-Cotransporter-2 in Neuropathic Pain

The pain sensory system normally functions under a fine balance between excitation and inhibition. When this balance is perturbed for some reason, it leads to neuropathic pain. There is accumulating evidence that attributes this pain generation to specific dysfunctions of the inhibitory system in the spinal cord. One possible mechanism leading to the induction of these dysfunctions is the down-regulation of K⁺-Cl^?-cotransporter-2 (KCC2) expression. In fact, various neuropathic pain models indicate a decrease of KCC2 expression in the spinal cord. The alteration of KCC2 expression affects GABAergic and glycinergic neurotransmissions, because KCC2 is a potassium-chloride exporter and serves to maintain intracellular chloride concentration. When there is a low level of KCC2 expression, GABAergic and glycinergic neurotransmissions transform from inhibitory signals to excitatory signals. In this review, the hypothesis that an alteration of KCC2 expression has a crucial influence on the initiation/development or maintenance of neuropathic pain is discussed. In addition, it is suggested that the alteration of inhibitory signals is dependent on the time after peripheral nerve injury.     

Phosrestide-1, a peptide derived from the Drosophila photoreceptor protein phosrestin I, is a potent substrate for Ca/calmodulin-dependent protein kinase II from rat brain

Multifunctional Ca²⁺/calmodulin-dependent protein kinase type II (CaMK II) plays a crucial role in mediation of cellular responses to rising cytosolic Ca²⁺ levels. We find that the novel peptide substrate PGTIEKKRSNAMKKMKSIEQHR serves as a highly potent substrate for CaMK II enzymes purified from both Drosophila and rat. The peptide is derived from a photoreceptor-specific protein, phosrestin I, of the Drosophila compound eye and is designated as phosrestide-1. Using saturating substrate concentrations, the enzymes from both species transfer the γ-phosphoryl group of ATP to phosrestide-1 at a level three to ten times greater than to the commercially available mammalian-derived CaMK II substrates, autocamtide-3 and syntide-2. This indicates a conservation of substrate preferences for CaMK II derived from distantly related species, a dipteran fly and a mammal. Although phosrestide-1 contains two potential serine residues for CaMK II phosphorylation, we find that only the C-terminal serine is phosphorylated by rat CaMK II. However, removal of the upstream sequence containing the N-terminal serine substantially reduced the potency of phosrestide-1 as a CaMK II substrate to a level comparable to that of syntide-2 or autocamtide-3. We also find that a peptide representing the N-terminal segment of phosrestide-1 does not inhibit either CaMK II. Therefore, the enhanced potency of phosrestide-1 as a CaMK II substrate is likely to be due to a preferred conformation of the peptide induced by the N-terminal segment rather than to a specific binding of the enzymes to the N-terminus of the peptide. To the best of our knowledge, phosrestide-1 is the first CaMK II substrate which is designed based on an invertebrate sequence. The high phosphorylation level of phosrestide-1 by CaMK II of mammalian origin may reflect highly conserved CaMK II signaling cascades between vertebrates and invertebrates.