IgY-binding peptide screened from a random peptide library as a ligand for IgY purification.

Chicken egg yolk immunoglobulin (IgY) is a functional substitute for mammalian IgG for antigen detection. Traditional IgY purification methods involve multi-step procedures resulting in low purity and recovery of IgY. In this study, we developed a simple IgY purification system using IgY-specific peptides identified by T7 phage display technology. From disulfide-constrained random peptide libraries constructed on a T7 phage, we identified three specific binding clones (Y4-4, Y5-14, and Y5-55) through repeated biopanning. The synthetic peptides showed high binding specificity to IgY-Fc and moderate affinity for IgY-Fc (Kd : Y4-4 = 7.3 ± 0.2 µM and Y5-55 = 4.4 ± 0.1 µM) by surface plasmon resonance analysis. To evaluate the ability to purify IgY, we performed immunoprecipitation and affinity high-performance liquid chromatography using IgY-binding peptides; the result indicated that these peptides can be used as affinity ligands for IgY purification. We then used a peptide-conjugated column to purify IgY from egg yolks pre-treated using an optimized delipidation technique. Here, we report the construction of a cost-effective, one-step IgY purification system, with high purity and recovery. © 2017 The Authors. Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.

Millennial scale maximum intensities of typhoon and storm wave in the northwestern Pacific Ocean inferred from storm deposited reef boulders.

Typhoons and associated storm waves in the northwestern Pacific Ocean commonly cause coastal disasters. The possibility remains that an even stronger typhoon than the strongest one observed to date might have occurred before. The development of a method to estimate a maximum intensity of past typhoons over thousands of years is important for paleoclimatology, paleoceanography and disaster prevention. Numerous storm wave boulders exist on reefs in the Ryukyu Islands, Japan, which have been deposited to their present position by the cumulative effects of the past storm waves. These boulders can be used as proxies for the hydrodynamic conditions of the largest waves from past events. Here, we present numerical computations for storm waves and boulder transport with the boulder distribution as a constraint factor to estimate the maximum intensities of storm waves and their causative typhoon events over the past 3500 years. Though the intensities of the maximum estimated waves and associated typhoon events were slightly stronger than those recorded over the past ~70 years in the Ryukyu Islands, our results suggest that no abnormally intense typhoon has struck the Ryukyu Islands in the past 3500 years. The potential impact from tsunamis remains uncertain; however, our results are meteorologically reasonable.

Clinical correspondence to hepatocellular carcinoma-related lesions with atypical radiological pattern.

In patients at risk of hepatocarcinogenesis, tumors are frequently detected with atypical radiological patterns related to hepatocellular carcinoma (HCC) on imaging studies. Despite their high potential for malignancy, whether to resect such lesions immediately is controversial. Based on histological findings, patients with non-enhanced tumors or enhanced tumors without washout were divided into two groups: those with tumors that should be treated containing well, moderately, and poorly differentiated HCC (Group 1), and those that can be observed containing early HCC, hepatocellular adenoma, focal nodular hyperplasia, dysplastic nodules, and regenerative nodules (Group 2), and we elucidated the clinical correspondence to these tumors. Seventy-two patients had a single tumor with atypical radiological pattern: 39 patients had HCC (Group 1), while 33 patients had benign tumors or early HCC (Group 2). Among nine baseline variables, serum α-fetoprotein (AFP) level in Group 1 (median, 13.2 ng/mL; range, 0.6-5881.6) was significantly higher than that in Group 2 (5.6 ng/mL; 0.8-86.3, P = 0.003). The cut-off value of AFP was 36.4 ng/mL for prediction of Group 1, and the median overall and recurrence-free survival periods of 23 patients in the high-AFP (≥ 36.4 ng/mL) group (5.3 years; 95%CI, 2.1 - N.A. and 1.6 years; 0.5-2.2) were significantly shorter than those of the 49 patients in the low-AFP (< 36.4) group (7.5 years; 7.5 - N.A., P = 0.047, and 2.8 years; 1.9-3.3, P = 0.001). Taken together, HCC-related tumors with an atypical radiological pattern could be observed unless serum AFP level is elevated.

Dynamic chirality determines critical roles for bioluminescence in symplectin-dehydrocoelenterazine system.

Symplectin is a photoprotein containing the dehydrocoelenterazine (DCL) chromophore, which links to a cysteine residue through a covalent bond with the emission of blue light. This study focuses on the stereochemical process of the emerging stereogenic centers. Two isomeric fluorinated DCL analogs (2,4-diF- and 2,6-diF-DCL) were employed owing to their different bioluminescence activities, these being 200% and 20% compared to natural DCL, respectively. Each of these diF-DCLs was found to exchange with the natural DCL in symplectin at pH 6.0. The emerging stereogenic carbons were racemic at the binding sites. Changing the pH of this storage form to the protein's optimum solubility pH (pH 7.8) resulted in 2,4-diF-DCL-bound symplectin luminescence, and the spent solutions were then analyzed and coelenteramide-390-CGLK-peptide and coelenteramine were detected after a peptidase digestion. The same analysis of the 2,6-diF-DCL-bound symplectin, on the other hand, afforded coelenteramine only but no coelenteramide. When the racemic storage diF-DCLs moved to the active site at pH 7.8, a change in the chirality with the 390-Cys residue resulted. Model experiments using L-cysteine-containing CGLK-peptide supported two diastereoisomers from each diF-DCL. The significant difference in the luminescence from these two chromophores is attributed to a plausible mechanism including the dynamically variable stereogenic center emerging at the storage and then the active site on the symplectin. It is concluded that such dynamic chirality plays a significant role in the symplectoteuthis bioluminescence.