Enzymes are biocatalysts. They are useful in environmentally friendly production processes and have high potential for industrial applications. However, because of problems with operational stability, cost, and catalytic efficiency, many enzymatic processes have limited applications. The use of cross-linked enzyme aggregates (CLEAs) has been introduced as an effective carrier-free immobilization method. This immobilization method is attractive because it is simple and robust, and unpurified enzymes can be used. Coimmobilization of different enzymes can be achieved. CLEAs generally show high catalytic activities, good storage and operational stabilities, and good reusability. In this review, we summarize techniques for the preparation of CLEAs for use as biocatalysts. Some important applications of these techniques in chemical synthesis and environmental applications are also included. CLEAs provide feasible and efficient techniques for improving the properties of immobilized enzymes for use in industrial applications.

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Elastin-like peptides (ELPs) consist of distinctive repetitive sequences, such as (VPGVG) , exhibit temperature-dependent reversible self-assembly (coacervation), and have been considered to be useful for the development of thermoresponsive materials. Further fundamental studies evaluating coacervative properties of novel nonlinear ELPs could present design concepts for new thermoresponsive materials. In this study, we prepared novel ELPs, cyclic (FPGVG) (cyclo[FPGVG] , n = 1-5), and analyzed their self-assembly properties and structural characteristics. Cyclo[FPGVG] ( n = 3-5) demonstrated stronger coacervation capacity than the corresponding linear peptides. The coacervate of cyclo[FPGVG] was able to retain water-soluble dye molecules at 40 °C, which implied that cyclo[FPGVG] could be employed as a base material of DDS (drug delivery system) matrices and other biomaterials. The results of molecular dynamics simulations and circular dichroism measurements suggested that a certain chain length was required for cyclo[FPGVG] to demonstrate alterations in molecular structure that were critical to the exhibition of coacervation.

An increase of nucleolar number and size has made nucleoli essential markers for cytology and tumour development. However, the underlying basis for their structural integrity and abundance remains unclear. Protein phosphatase PPM1D was found to be up-regulated in different carcinomas including breast cancers. Here, we demonstrate for the first time that PPM1D regulates nucleolar formation via inducing an increased phosphorylation of the nucleolar protein NPM. We show that PPM1D overexpression induces an increase in the nucleolar number regardless of p53 status. We also demonstrated that specific sequential phosphorylation of NPM is important for nucleolar formation and that PPM1D is a novel upstream regulator of this phosphorylation pathway. These results enhance our understanding of the molecular mechanisms that govern nucleoli formation by demonstrating that PPM1D regulates nucleolar formation by regulating NPM phosphorylation status through a novel signalling pathway, PPM1D-CDC25C-CDK1-PLK1.

Histone deacetylase (HDAC) inhibitors belong to a new class of potential anticancer agents. It may be possible to reduce some of the toxicity by specifically targeting only the HDAC isoform. Here, stereoisomeric HDAC inhibitors containing fluoroalkene were analyzed for their specificity toward HDAC isoforms. Z-Form 1(Z) showed high affinity to HDACs whereas E-isoform 1(E) had lower affinity to HDAC1 and HDAC4. These data suggested that introduction of alkene with E/Z configuration to HDAC inhibitor can be a new strategy to develop the isoform-selective HDAC inhibitors.Histone deacetylases (HDACs) have crucial roles in numerous biological processes. There are eighteen encoded human HDACs, which are classified as class I (HDAC1, -2, -3, and -8), class II (HDAC4, -5, -6, -7, -9, and -10), class III (SIRT1-7), and class IV (HDAC11) enzymes. Recent studies of knockout mice lacking HDAC genes have revealed highly specific functions for individual HDAC isoforms.1 These facts emphasize the importance of developing HDAC-isoform specific inhibitors.A number of HDAC inhibitors have been reported to date, and they were used as anticancer drugs and reagents for serial animal cloning without clone-specific abnormalities.2,3 HDAC inhibitors, including SAHA, typically consist of a zinc-binding group that coordinates to the catalytic metal atom within the HDAC active site, a linker that accommodates the tubular access of the active site, and a capping group that interacts with the residues at the entrance of the active site. It is very important to have moieties to enhance isoform selectivity to reduce side effects. Replacement of hydroxamic acid as the zinc-binding group has been carried out to produce new types of HDAC isozyme-selective inhibitors.2 Recently, we developed HDAC inhibitors containing a sulfanylmethyl group attached with fluoroalkene. As the fluoroalkene is known for nonhydrolyzable amide mimetic, it is stable with respect to hydrolytic cleavage. 4 The thiol group may interact with zinc ion in a chelating manner 5 (Figure 1). The Z-isomer 1(Z) compound showed the stronger general HDAC inhibitory activity using HeLa extract than SAHA. 6 Here, we designed and synthesized the stereoisomer, E-isomer 1(E) to control the special configuration of thiol group. The effects of E-and Z-isomers on HDAC inhibitory activity and selectivity were analyzed against various HDAC-isoforms.The synthesis of 1(E) is outlined in Scheme 1. As outlined in Scheme 1, synthesis of the complementary 1(E) was started from bromide A, which was used for preparation of Z-isomer.