Bidirectional embodied association between debt and physical burden.

There is a Chinese proverb saying that "when the debts are paid, the body feels light." From the perspective of embodied cognition, there may be a connection between indebtedness and the sensation of physical burden. However, the relationship between the two aspects has not been fully examined.

A recombinant chimeric spider pyriform-aciniform silk with highly tunable mechanical performance.

Spider silks are natural protein-based biomaterials which are renowned for their mechanical properties and hold great promise for applications ranging from high-performance textiles to regenerative medicine. While some spiders can produce several different types of silks, most spider silk types - including pyriform and aciniform silks - are relatively unstudied. Pyriform and aciniform silks have distinct mechanical behavior and physicochemical properties, with materials produced using combinations of these silks currently unexplored.

H, N and C backbone resonance assignments of the acidic domain of the human MDM2 protein.

The human MDM2 protein regulates the tumor suppressor protein p53 by restricting its transcriptional activity and by promoting p53 degradation. MDM2 is ubiquitously expressed, with its overexpression implicated in many forms of cancer. The inhibitory effects of MDM2 on p53 have been shown to involve its N-terminal p53-binding domain and its C-terminal RING domain.

Prp8 Intein: An In Vivo Target-Based Drug Screening System in to Identify Protein Splicing Inhibitors and Explore Its Dynamics.

Inteins are genetic mobile elements that are inserted within protein-coding genes, which are usually housekeeping genes. They are transcribed and translated along with the host gene, then catalyze their own splicing out of the host protein, which assumes its functional conformation thereafter. As Prp8 inteins are found in several important fungal pathogens and are absent in mammals, they are considered potential therapeutic targets since inhibiting their splicing would selectively block the maturation of fungal proteins.

The MDMX acidic domain competes with the p53 transactivation domain for MDM2 N-terminal domain binding.

The tumor suppressor protein p53 governs many cellular pathways to control genome integrity, metabolic homeostasis, and cell viability. The critical roles of p53 highlight the importance of proper control over p53 in maintaining normal cellular function, with the negative regulators MDM2 and MDMX playing central roles in regulating p53 activity. The interaction between p53 and either MDM2 or MDMX involves the p53 transactivation domain (p53TD) and the N-terminal domains (NTD) of MDM2 or MDMX.

H, N and C backbone resonance assignments of the acidic domain of the human MDMX protein.

The human MDMX protein, also known as MDM4, plays a pivotal role in regulating the activity of the tumor suppressor protein p53 by restricting p53 transcriptional activity and stimulating the E3 ubiquitin ligase activity of another key regulatory protein, MDM2, to promote p53 degradation. MDMX is ubiquitously expressed in most tissue types and overexpression of MDMX has been implicated in many forms of cancer. MDMX has been shown to require an intact N-terminal p53-binding domain and C-terminal RING domain to exert inhibitory effects on p53.

Prevalence and Genotype Distribution of Human Papillomavirus From 9,182 Individuals Participated Health Examination.

Background: Human papillomavirus (HPV) is the cause of nearly all cervical cancers and the primary cause of anal cancers. Prevalence of HPV varies largely among countries and regions, and population-based data are largely insufficient. The aim of this study is to determine the prevalence and genotype distribution of HPV infection among the women received a general health check.

Structure, amphipathy, and topology of the membrane-proximal helix 8 influence apelin receptor plasma membrane localization.

G-protein coupled receptors (GPCRs) typically have an amphipathic helix ("helix 8") immediately C-terminal to the transmembrane helical bundle. To date, a number of functional roles have been associated with GPCR helix 8 segments, but structure-function analysis for this region remains limited. Here, we examine helix 8 of the apelin receptor (AR or APJ), a class A GPCR with wide physiological and pathophysiological relevance.

Engineered DnaX inteins for protein splicing with flanking proline residues.

Inteins are internal protein sequences capable of catalyzing a protein splicing reaction by self-excising from a precursor protein and simultaneously joining the flanking sequences with a peptide bond. Split inteins have separate pieces (N-intein and C-intein) that reassemble non-covalently to catalyze a protein -splicing reaction joining two polypeptides. Protein splicing has become increasingly useful tools in many fields of biological research and biotechnology.

Recombinant Silk Fiber Properties Correlate to Prefibrillar Self-Assembly.

Spider silks are desirable materials with mechanical properties superior to most synthetic materials coupled with biodegradability and biocompatibility. In order to replicate natural silk properties using recombinant spider silk proteins (spidroins) and wet-spinning methods, the focus to date has typically been on modifying protein sequence, protein size, and spinning conditions. Here, an alternative approach is demonstrated.

Structural and Mechanical Roles for the C-Terminal Nonrepetitive Domain Become Apparent in Recombinant Spider Aciniform Silk.

Spider aciniform (or wrapping) silk is the toughest of the seven types of spider silks/glue due to a combination of high elasticity and strength. Like most spider silk proteins (spidroins), aciniform spidroin (AcSp1) has a large core repetitive domain flanked by relatively short N- and C-terminal nonrepetitive domains (the NTD and CTD, respectively). The major ampullate silk protein (MaSp) CTD has been shown to control protein solubility and fiber formation, but the aciniform CTD function remains unknown.

Characterizing Aciniform Silk Repetitive Domain Backbone Dynamics and Hydrodynamic Modularity.

Spider aciniform (wrapping) silk is a remarkable fibrillar biomaterial with outstanding mechanical properties. It is a modular protein consisting, in Argiope trifasciata, of a core repetitive domain of 200 amino acid units (W units). In solution, the W units comprise a globular folded core, with five α-helices, and disordered tails that are linked to form a ~63-residue intrinsically disordered linker in concatemers.

Identification of Wet-Spinning and Post-Spin Stretching Methods Amenable to Recombinant Spider Aciniform Silk.

Spider silks are outstanding biomaterials with mechanical properties that outperform synthetic materials. Of the six fibrillar spider silks, aciniform (or wrapping) silk is the toughest through a unique combination of strength and extensibility. In this study, a wet-spinning method for recombinant Argiope trifasciata aciniform spidroin (AcSp1) is introduced.

Tracking Transitions in Spider Wrapping Silk Conformation and Dynamics by (19)F Nuclear Magnetic Resonance Spectroscopy.

Aciniform silk protein (AcSp1) is the primary component of wrapping silk, the toughest of the spider silks because of a combination of high tensile strength and extensibility. Argiope trifasciata AcSp1 contains a core repetitive domain with at least 14 homogeneous 200-amino acid units ("W" units). Upon fibrillogenesis, AcSp1 converts from an α-helix-rich soluble state to a mixed α-helical/β-sheet conformation.

Current strategies for protein production and purification enabling membrane protein structural biology.

Membrane proteins are still heavily under-represented in the protein data bank (PDB), owing to multiple bottlenecks. The typical low abundance of membrane proteins in their natural hosts makes it necessary to overexpress these proteins either in heterologous systems or through in vitro translation/cell-free expression. Heterologous expression of proteins, in turn, leads to multiple obstacles, owing to the unpredictability of compatibility of the target protein for expression in a given host.

Cysteine-free non-canonical C-intein for versatile protein C-terminal labeling through trans-splicing.

Site-specific protein labeling are powerful means of protein research and engineering; however, new and improved labeling methods are greatly needed. Split inteins catalyze a protein trans-splicing reaction that can be used for enzymatic and nearly seamless protein labeling. Non-canonical S11 split intein has been used in an earlier method of protein C-terminal labeling; however, its relatively large (~150 aa) N-intein fused to the target protein often hindered protein expression, folding, and solubility.

Spider wrapping silk fibre architecture arising from its modular soluble protein precursor.

Spiders store spidroins in their silk glands as high concentration aqueous solutions, spinning these dopes into fibres with outstanding mechanical properties. Aciniform (or wrapping) silk is the toughest spider silk and is devoid of the short amino acid sequence motifs characteristic of the other spidroins. Using solution-state NMR spectroscopy, we demonstrate that the 200 amino acid Argiope trifasciata AcSp1 repeat unit contrasts with previously characterized spidroins, adopting a globular 5-helix bundle flanked by intrinsically disordered N- and C-terminal tails.

Segmental expression and C-terminal labeling of protein ERp44 through protein trans-splicing.

Endoplasmic reticulum resident protein 44 (ERp44) is a member of the protein disulfide isomerase family and functions in oxidative protein folding in the endoplasmic reticulum. A structurally flexible C-terminal tail (C-tail) of ERp44 plays critical roles in dynamically regulating ERp44's function in protein folding quality control. The structure-function dynamics of ERp44's C-tail may be studied further using fluorescence and other techniques, if methods are found to label the C-tail site-specifically with a fluorescent group or segmentally with other desired labels.

[Changes of IFN-gamma, IL-4 and T cells in Schistosoma japonicum-infected mice after praziquantel treatment].

Objective: To investigate the serum levels of IFN-gamma and IL-4, and the dynamic changes of IFN-gamma-specific and IL-4-specific lymphocytes in mice with Schistosoma japonicum infection after treatment by praziquantel.

Methods: Ninety BALB/c mice were randomly divided into three groups (n = 30) named as infection group, treatment group and control group. The mice in treatment group and infection group were infected with (25 +/- 2) S.

Small expression tags enhance bacterial expression of the first three transmembrane segments of the apelin receptor.

G-protein coupled receptors (GPCRs) are inherently dynamic membrane protein modulators of various important cellular signaling cascades. The apelin receptor (AR or APJ) is a class A GPCR involved in numerous physiological processes, implicated in angiogenesis during tumour formation and as a CD4 co-receptor for entry of human immunodeficiency virus type 1 (HIV-1) to cells. Due to the lack of efficient methods to produce full-length GPCRs enriched with nuclear magnetic resonance (NMR) active (15)N, (13)C, and (or) (2)H isotopes, small GPCR fragments typically comprising 1-2 transmembrane segments are frequently studied using NMR spectroscopy.

Preferential apelin-13 production by the proprotein convertase PCSK3 is implicated in obesity.

The peptide hormone apelin is translated as a 77-residue preproprotein, truncated to the 55-residue proapelin and, subsequently, to 13-36-residue bioactive isoforms named apelin-13 to -36. Proapelin is hypothesized to be cleaved to apelin-36 and then to the shorter isoforms. However, neither the mechanism of proapelin processing nor the endoproteases involved have been determined.

Nanoparticle self-assembly by a highly stable recombinant spider wrapping silk protein subunit.

Artificial spider silk proteins may form fibers with exceptional strength and elasticity. Wrapping silk, or aciniform silk, is the toughest of the spider silks, and has a very different protein composition than other spider silks. Here, we present the characterization of an aciniform protein (AcSp1) subunit named W1, consisting of one AcSp1 199 residue repeat unit from Argiope trifasciata.

Protein trans-splicing of multiple atypical split inteins engineered from natural inteins.

Protein trans-splicing by split inteins has many uses in protein production and research. Splicing proteins with synthetic peptides, which employs atypical split inteins, is particularly useful for site-specific protein modifications and labeling, because the synthetic peptide can be made to contain a variety of unnatural amino acids and chemical modifications. For this purpose, atypical split inteins need to be engineered to have a small N-intein or C-intein fragment that can be more easily included in a synthetic peptide that also contains a small extein to be trans-spliced onto target proteins.

Recombinant minimalist spider wrapping silk proteins capable of native-like fiber formation.

Spider silks are desirable biomaterials characterized by high tensile strength, elasticity, and biocompatibility. Spiders produce different types of silks for different uses, although dragline silks have been the predominant focus of previous studies. Spider wrapping silk, made of the aciniform protein (AcSp1), has high toughness because of its combination of high elasticity and tensile strength.

Protein trans-splicing of an atypical split intein showing structural flexibility and cross-reactivity.

Inteins catalyze a protein splicing reaction to excise the intein from a precursor protein and join the flanking sequences (exteins) with a peptide bond. In a split intein, the intein fragments (I(N) and I(C)) can reassemble non-covalently to catalyze a trans-splicing reaction that joins the exteins from separate polypeptides. An atypical split intein having a very small I(N) and a large I(C) is particularly useful for joining synthetic peptides with recombinant proteins, which can be a generally useful method of introducing site-specific chemical labeling or modifications into proteins.