Consecutive treatment with phytase and arazyme influence protein hydrolysis of soybean meal

Soybean meal (SBM) is the main protein supplement used in animal feed worldwide. The degree of hydrolysis (DH) of SBM treated with two enzymes viz. phytase and arazyme was investigated for the first time in this study. The DH of SBM in the treatment with arazyme increased significantly as compared to the control without enzyme application. About 1.5-times and 10-fold higher DH were observed in phytase treatment when compared to the control treatments containing no enzyme. At the end of 24 h, enzymatic hydrolysis was done through consecutive treatment with 0.5% (w/v) phytase and 0.02% (w/v) arazyme, and the protein in the hydrolysate were mostly degraded free amino acids and peptides (<6 KDa) when SDS-PAGE and fast protein liquid chromatography (FPLC) techniques used. Free amino acids contents of the soybean meal treated with phytase-arazyme increased by 2 to 14 fold as compared to products without enzyme. These results suggested that soybean meal proteins continuously treated with phytase and arazyme can be used as commercial feed additive for accelerated livestock growth.Key words: Soybean meal, phytase, arazyme, hydrolysis

A microRNA profile of human CD8(+) regulatory T cells and characterization of the effects of microRNAs on Treg cell-associated genes.

Recently, regulatory T (Treg) cells have gained interest in the fields of immunopathology, transplantation and oncoimmunology. Here, we investigated the microRNA expression profile of human natural CD8(+)CD25(+) Treg cells and the impact of microRNAs on molecules associated with immune regulation. We purified human natural CD8(+) Treg cells and assessed the expression of FOXP3 and CTLA-4 by flow cytometry. We have also tested the ex vivo suppressive capacity of these cells in mixed leukocyte reactions. Using TaqMan low-density arrays and microRNA qPCR for validation, we could identify a microRNA 'signature' for CD8(+)CD25(+)FOXP3(+)CTLA-4(+) natural Treg cells. We used the 'TargetScan' and 'miRBase' bioinformatics programs to identify potential target sites for these microRNAs in the 3'-UTR of important Treg cell-associated genes. The human CD8(+)CD25(+) natural Treg cell microRNA signature includes 10 differentially expressed microRNAs. We demonstrated an impact of this signature on Treg cell biology by showing specific regulation of FOXP3, CTLA-4 and GARP gene expression by microRNA using site-directed mutagenesis and a dual-luciferase reporter assay. Furthermore, we used microRNA transduction experiments to demonstrate that these microRNAs impacted their target genes in human primary Treg cells ex vivo. We are examining the biological relevance of this 'signature' by studying its impact on other important Treg cell-associated genes. These efforts could result in a better understanding of the regulation of Treg cell function and might reveal new targets for immunotherapy in immune disorders and cancer

The Microprocessor controls the activity of mammalian retrotransposons

More than half of the human genome is made of transposable elements whose ongoing mobilization is a driving force in genetic diversity; however, little is known about how the host regulates their activity. Here, we show that the Microprocessor (Drosha-DGCR8), which is required for microRNA biogenesis, also recognizes and binds RNAs derived from human long interspersed element 1 (LINE-1), Alu and SVA retrotransposons. Expression analyses demonstrate that cells lacking a functional Microprocessor accumulate LINE-1 mRNA and encoded proteins. Furthermore, we show that structured regions of the LINE-1 mRNA can be cleaved in vitro by Drosha. Additionally, we used a cell culture–based assay to show that the Microprocessor negatively regulates LINE-1 and Alu retrotransposition in vivo. Altogether, these data reveal a new role for the Microprocessor as a post-transcriptional repressor of mammalian retrotransposons and a defender of human genome integrity.S.R.H. was supported by a Marie Curie Intra-European Fellowship and a Marie Curie CIG-Grant (PCIG10-GA-2011-303812). M.P. and E.E. were supported by the Spanish Ministry of Science (BIO2011-23920) and by the Sandra Ibarra Foundation (CSD2009-00080). M.P. is supported by the Novo Nordisk Foundation. J.L.G.-P. is supported by FP7-PEOPLE-2007-4-3-IRG, CICE-FEDER-P09-CTS-4980, PeS-FEDER-PI-002, FIS-FEDER-PI11/01489 and the Howard Hughes Medical Institute (IECS-55007420). J.F.C. was supported by Core funding from the Medical Research Council and by the Wellcome Trust (grant 095518/B/11/Z)

Electronic structures of Ga-induced incommensurate and commensurate overlayers on the Si(111) surface

Electronic band structures of Ga-induced dense overlayers on the Si(111) surface have been investigated using angle-resolved photoelectron spectroscopy and first-principle density-functional theory calculations. The well-known incommensurate 6.3 x 6.3 phase formed by the growth on the Si(111)7x7 surface and the newly found 1 x 1 phase grown on the preformed Si(111)root 3 x root 3-Ga surface are characterized in detail. A highly dispersive surface state (S) is observed for the incommensurate phase but only a weakly dispersing one (S') for the 1 x 1 surface. Both surfaces are found to be nonmetallic, with their surface states fully occupied. The theoretical calculation reproduces well the S band of the 6.3 x 6.3 phase on the basis of a simple 1 x 1 Ga-Si bilayer structure formed with substitutional Ga atoms, which was proposed previously. No explicit sign of the incommensurate periodicity is found in the measured band dispersions, indicating a very weak incommensurate potential. The S band is shown to originate in the sp(2)-like planar bonds within the Ga-Si bilayer. The width of the S band is sensitive to the surface strain in the calculation and about 8% expansion of the Ga-Si bilayer lattice was needed to reproduce the measured dispersions, which is in good agreement with the previous X-ray study. On the other hand, the surface state S of the commensurate 1 x 1 phase cannot be explained by any simple model of a substitutional or adsorbed Ga layer. Further structural studies are thus requested. The second Ga layer, which is metallic, grows two-dimensionally over this 1 x 1 layer up to a total coverage of about 5 ML. (C) 2010 Elsevier B.V. All rights reserved.X1165sciescopu