Biochemistry articles within Polymer Journal

Featured

  • Original Article
    | Open Access

    Hydrogels have attracted considerable attention in the biomedical applications because of their high functionalities, biocompatibility and biodegradability. This study on the novel hyaluronic acid (HA) nanogel-based hydrogel comprising HA modified with cholesterol derivatives and maleimide crosslinking groups. Depending on the degree of cholesterol derivative substitution, the properties such as water uptake, gelation behavior and protein encapsulation was investigated. The results suggested that the hydrogels enhanced peptide and protein trapping abilities have potential as a new hyaluronan hydrogel for biomedical applications.

    • Kohei Yabuuchi
    • , Toru Katsumata
    •  & Akio Kishida

  • Original Article |

    Ester free type trimethylene carbonate derivatives bearing bulky aromatic groups were designed and synthesized, including one or two benzyl groups, diphenylmethyl groups, and triphenylmethyl groups. The mechanical properties of the polymers were estimated by compressive test, resulting in around 0.3MPa at most. The degradation behaviors were also evaluated under Lipase solution and 0.01M NaOHaq. for several weeks, revealing the substituents influenced on the prevention of degradation at most cases. The degradation behavior was slowly observed, which were analyzed by weight loss, SEM images, SEC, TGA, and DSC.

    • Rikyu Miyake
    •  & Hiroharu Ajiro

  • Original Article |

    Lentinan (Len) is a linear (1,3)-β-d-glucan with two of its five main-chain glucose-bearing (1,6)-β-d-glucan side chains and has been clinically used for cancer treatment in combination with chemotherapy. In this paper, a structural analysis of Len was conducted using SAXS, GPC, and 13C quantitative NMR techniques, and a comparative study with other β-glucans was performed. The complexation between dA40 and Len caused the hypochromic effect. Len and dA40 showed a similar complexation with that of SPG; two main chain glucoses bind to one dA moiety by GPC.

    • Takuya Matsunaga
    • , Kazuki Sumiya
    •  & Kazuo Sakurai

  • Original Article
    | Open Access

    The density-dependent changes of avidities between Siglec-8 and the glycan ligand of the α(2 → 6)-sialyl-6-sulfo-N-acetyllactosamine derivative (1) were investigated for the first time. The SAM surfaces with different glycan densities were constructed by changing the ratio of 1 and 3,3′-dithiodipropionic acid (DTPA) on the gold electrode of the quartz crystal microbalance (QCM). Next, we measured the apparent KD values of 1 with Siglec-8 on the SAM surfaces by the QCM to investigate the effect of the glycan density on the avidity of the Siglec-8 interaction. The results obtained in this study suggest that Siglec-8 has an optimal glycan density (~9.2 × 102 molecules μm−2) for preferred interactions.

    • Risa Naka
    • , Simon Sau Yin Law
    •  & Masashi Ohmae

  • Focus Review |

    Nucleobase modification of acyclic XNA oligomers achieved functionalization for use as a novel fluorescent probe and photoswitching system. A linear probe, composed of serinol nucleic acid (SNA) and 5-perylenylethynyl uracil residues, enabled quantitative detection of target RNA through a visually observable change in fluorescent color and intensity. A photoresponsive SNA with two 8-pyrenylvinyl adenine (PVA) residues established photocontrol of SNA/RNA duplex formation and dissociation. Using a combination of 8-naphthylvinyl adenine (NVA) and PVA demonstrated orthogonal photocontrol system. Thus, nucleobase modifications further expand the utility of acyclic XNA in bionanotechnology.

    • Keiji Murayama
    • , Yuuhei Yamano
    •  & Hiroyuki Asanuma

  • Note |

    The new strategy of two different AS-ODNs (targeting K-ras and YB-1) being delivered simultaneously to the same target cancer cell was investigated using the quantized complex made from AS-ODNs and short β-glucan (schizophyllan (SPG)). We used the quantized complex properties to prepare both end complexes with AS-ODNs on both ends. Both end complexes silenced two target genes and showed high inhibition of cancer cell growth. The results indicate that both end complexes can deliver two antisense sequences at the same time and show a synergistic effect.

    • Yuki Hata
    • , Kazuki Sumiya
    •  & Kazuo Sakurai

  • Original Article |

    We describe the synthesis of polycarbonate (PC) by means of the polycondensation of diol formate and dialkyl carbonate through an ester-carbonate exchange reaction. Furthermore, the polycondensation of diol formate and diethyl carbonate in the presence of polyester (PEs) under reduced pressure affords a statistical copolymer of PC and PEs. The composition of PC and PEs in the copolymer can be arbitrarily altered by changing the feed ratio of the monomers to PEs.

    • Takayoshi Katoh
    • , Maai Saso
    •  & Tsutomu Yokozawa

  • Focus Review |

    This focus review describes a biosensing strategy called “chemical tongue”, which mimics the human taste system by employing fluorogenic materials containing various chemical structures in conjunction with statistical techniques. The focus is on the design of polymer-based chemical tongues and their applications with various complex biological samples. The chemical-tongue strategy is capable of recognizing biological samples in a unique manner that does not, in contrast to conventional approaches, rely on specific interactions, thereby potentially opening avenues for unexplored uses of polymers in a wide range of research areas.

    • Shunsuke Tomita

  • Original Article |

    A cell-cultivable gel based on a polysaccharide “sacran” has been developed. Although the conventionally produced sacran gel does not show cell adhesion, it achieved compositing with collagen, which has cell adhesion, and showed its potential as a cell scaffold. The feature of this study is that the gelation of sacran was controlled by the addition of salt, and the composite with collagen was achieved for the first time.

    • Kenji Takada
    • , Asuka Komuro
    •  & Tatsuo Kaneko

  • Review |

    The present review focuses on the enzymatic synthesis of unnatural oligosaccharides and polysaccharides linked through strictly controlled α(1→4)-glycosidic linkages by glucan phosphorylase (GP) catalysis. In particular, the recent progress of the enzymatic synthesis of unnatural polysaccharides by GP (isolated from thermophilic bacteria, Aquifex aeolicus VF5)-catalyzed polymerization and related reactions is overviewed. The unnatural substrates have high applicability as practical functional materials in pharmaceutical, medicinal, and biological research fields.

    • Jun-ichi Kadokawa

  • Original Article
    | Open Access

    Cellulose chains with a reducing-end thiol group are of interest to install a controllable topochemical pattern of site-selective modification into nanocellulose materials. Selection of the polymerizing enzyme (cellodextrin phosphorylase; CdP) was pursued here to enhance the synthetic precision in the preparation of 1-thio-cellulose. The CdP from Clostridium stercorarium (CsCdP) was identified as a practical catalyst for 1-thio-cellulose synthesis in high purity (≥95%) directly from β-1-thio-glucose. The synthesis proceeds without the need of cellobiose phosphorylase (CbP) and minimizes the contamination (plain cellulose; ≤5%) in the product.

    • Chao Zhong
    •  & Bernd Nidetzky

  • Focus Review |

    A supramolecular complex termed “hemoCD1” was constructed as the aqueous synthetic Hb/Mb model using a 1:1 inclusion complex of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphinatoiron(II) with a per-O-methylated β-cyclodextrin dimer with a pyridine linker. HemoCD1 was used as a selective CO scavenger in vivo due to its extremely high binding affinity to CO. In addition, hemoCD1 was utilized to quantify the accumulation of endogenous and exogenous CO in organs/tissues. Finally, hemoCD1 was employed as an antidote for CO poisoning in animals.

    • Hiroaki Kitagishi
    •  & Qiyue Mao

  • Review |

    Hydrophobically modified polysaccharides have attracted considerable attention in the biomedical field because of their biocompatibility, biodegradability, and nontoxicity. This article reviews previous studies on micellar structures formed by hydrophobically modified polysaccharides (pullulan and amylose) in aqueous solutions by static and dynamic light scattering, small angle X-ray and neutron scattering, and fluorescence from pyrene solubilized in the polymer solution. Depending on the degree of substitution, the hydrophobically modified polysaccharides exist in aqueous solution as full or loose flower necklaces or as nanogels made up of randomly branched polymers.

    • Takahiro Sato
    • , Jia Yang
    •  & Ken Terao

  • Focus Review |

    Relationship between the primary structures and their properties is recognized as an important research subject for polymer chemists. To make progress in this academic field, innovative synthetic procedures of cyclic polymers are essential. The synthetic strategy has two typical pathways: one is the ring closure of functional linear polymers and the other is ring expansion polymerization using cyclic monomers, an initiator, or a catalyst. This focus review deals with the recent synthetic evolution of cyclic polymers, focusing on our new strategy: ring closing without highly dilute conditions.

    • Yuki Muramatsu
    •  & Akinori Takasu

  • Original Article |

    In this work, we employed Carbothane® electrospun matrices (PCU) for lysine surface modification, using oligomers obtained from allyl glycidyl ether (AGE) reaction as spacers. The incorporation of AGE oligomers significantly reduced the nonspecific protein adsorption, while further modification with lysine led to a more pronounced decrease. The lysine-modified matrices presented increased plasminogen adsorption capacity and in vitro clot lysis ability, confirming the plasminogen adsorption selectivity and thus improving the hemocompatibility behavior of these matrices.

    • Alfonso Pepe
    • , Maria Gabriela Guevara
    •  & Pablo Christian Caracciolo

  • Original Article |

    This study presents a simple and general platform for the efficient loading and delivery of proteins using a methoxy-poly(ethylene glycol)-block-poly(L-phosphotyrosine) (mPEG-b-PpY)-templated calcium phosphate (CaP) hybrid nanoparticle. Recombinant proteins bearing a histidine tag can be conveniently loaded onto the hybrid CaP nanoparticles doped with Zn2+ (CaP-Zn) by coordination. Nanoparticle can be protected the protein from proteolytic degradation and effectively delivered to intracellular spaces. This work may open up opportunities for intracellular delivery of recombinant protein therapeutics.

    • Haisen Zhou
    • , Yaoyi Wang
    •  & Hua Lu

  • Original Article |

    Dissolved polymers directed molecular crystallization behavior under dilute and crowding conditions. Larger poly(ethylene glycol)s (PEGs) accelerated caffeine crystal formation in the dilute regime of PEG solutions, which was attributed to the depletion attraction that promoted caffeine cluster aggregation into crystal nuclei. In the semidilute regime, the crystal formation rate was insensitive to the molecular weight of PEGs. This observation was consistent with polymer blob properties, which govern depletion attraction and maintain a constant size at a given polymer concentration, irrespective of molecular weight in the semidilute regime.

    • Yuuki Hata
    • , Xiang Li
    •  & Takamasa Sakai

  • Original Article |

    We examined drug release behavior and anticancer efficacy of cyclodextrin-based nanoparticles (CDNPs) containing alpha-mangostin (MGS) in three different type of CDs (α-, β-, and γ-CD). βCDNP containing MGS demonstrated the best anticancer efficacy, while no efficacy was observed for the other CDNPs. Our findings suggested the anticancer efficacy might depend on the drug retention capability in which the interior and surface CDs in the CDNPs relate to the slow and rapid release modes, respectively. We assume the drug retention capability of slow release mode is important for performing the anticancer efficacy.

    • Van T. H. Doan
    • , Shin Takano
    •  & Kazuo Sakurai

  • Focus Review |

    Water-soluble Naphthalene diimide (NDI) binds to the DNA duplex via threading intercalation mode. This has provided unique DNA analytical techniques, functional DNA polymers, and supramolecular polymers. Especially the ferrocene-containing NDIs, having electrochemically active sites, has been applied to an electrochemical gene detection system and also utilized in the precision analysis of genes and single nucleotide polymorphisms. Recently, NDI derivatives have been recognizing as potential candidate for anticancer therapeutics and for designing a unique cancer-detection system.

    • Shigeori Takenaka

  • Original Article |

    We chose an autoinduction (IPTG-independent) system for overexpression of recombinant proteins using E. coli as the expression host. In autoinduction, glucose and lactose are used as main carbon sources for cell growth. When the glucose is almost completely consumed as the first growth of E. coli., the carbon source turns to lactose, accompanied by regioselective chemical transformation of lactose to allolactose, which acts as the trigger for activation of transcription by releasing the repressor. Using this system, we achieved marked overexpression of the biosynthesized GFP and aECM-CS5-ELF.

    • Kaho Kataoka
    •  & Akinori Takasu

  • Focus Review |

    It was found that a synthetic 24-mer β-annulus peptide, which participates in the formation of the dodecahedral internal skeleton of the tomato bushy stunt virus capsid, spontaneously self-assembled into artificial viral capsids with a size of 30–50 nm. The artificial viral capsids could be dressed up with gold nanoparticles, single-stranded DNA, coiled-coil spikes, and proteins by modifying with these molecules at the C-terminus of β-annulus peptides. The artificial viral capsids were notably stabilized by dressing up with human serum albumin and acquired enzymatic activity by dressing up with ribonuclease.

    • Kazunori Matsuura

  • Focus Review |

    Recent advancements in DNA nanotechnology and nanobioengineering allowed the use of DNA as a generic material. Notably, an enzyme-based fabrication method of physical DNA hydrogels opened up a route to realize a novel class of DNA-based materials. Different forms of DNA materials with new applications were created by utilizing its unique characteristics. This Focus Review provides a brief overview of the enzyme-based fabrication method of physical DNA hydrogels and discusses the latest developments in the field.

    • Shogo Hamada
    •  & Dan Luo

  • Original Article |

    In this study, we synthesized and characterized cyclodextrin-based nanoparticles (CDNPs) by polyaddition reactions using epichlorohydrin and three different type of CDs (α-, β-, and γ-CD). We found that cyclodextrin tended to cover surface of our nanoparticles; while epichlorohydrin network enlarged when weight ratio of epichlorohydrin/cyclodextrin increased. Our CDNPs demonstrated a very high loading ratio against α-mangostin (MGS), and getting close to 1:1 ratio.

    • Van T. H. Doan
    • , Ji Ha Lee
    •  & Kazuo Sakurai

  • Original Article |

    The solution-state macromolecular structure of highly 1,6-glucose-branched β-1,3-glucan (6BG3) was elucidated by modifying and complexing with chromophoric reporters. The reporter-modified 6BG3 forms the globule through the random coil-to-globule conversion process. Hybridizing 6BG3 with the polythiophene reporter affords the loose heteroduplex rather than the tight heterotriplex, indicating the formation of the loose homoduplex of 6BG3.

    • Koichi Tamano
    • , Kotoe Nakasha
    •  & Gaku Fukuhara

  • Review |

    The cationic comb-type copolymers, which consisted of a polycation backbone grafted with high density of hydrophilic chains, form soluble and soft interpolyelectrolyte complexes with biopolymers and act as an artificial chaperone to assist in the folding of nucleic acids and peptides. The copolymers stabilize DNA duplex, triplex, and quadruplex structures and accelerate strand exchange reactions as well as assist in the folding of functional peptides into the active conformation.

    • Orakan Hanpanich
    •  & Atsushi Maruyama

  • Original Article |

    The adhesion force between the tentacle of a live cypris and polymer brushes on the sidewall of cover glass was directly measured by scanning probe microscopy in seawater. The cypris was immobilized on the cantilever with glue, and then forced to make contact with the modified surface. When the tentacle was detached by moving the cantilever away from the surface, the torsion of the cantilever caused the laser deflection on the photodiode corresponding to the adhesion force. Polymer brush surfaces exhibited extremely low adhesion to the cypris larva.

    • Shohei Shiomoto
    • , Yuka Yamaguchi
    •  & Motoyasu Kobayashi

  • Original Article |

    Double helical polysaccharide, xanthan samples with varying molar mass were thermally denatured and renatured in dilute solutions. The molar mass decreased after denaturation and renaturation for samples with an initial molar mass of 106 g mol−1, but those for the samples with an initial molar mass of 105 or 107 g mol−1 decreased only slightly. A model explaining this molar mass dependence of the denaturation and renaturation behaviors was proposed based on the experimental results.

    • Yasuhiro Matsuda
    • , Kazuya Okumura
    •  & Shigeru Tasaka

  • Original Article |

    Saturation transfer difference (STD) NMR analysis was performed to identify the titanium-binding peptide (TBP) sites that interact with the SiO2 nanoparticle surface, and then Arg1 and Asp5 were identified to be in close contact with the surface. The structure of the TBP bound to SiO2 determined by the NOESY measurement was well defined, and the Arg1 and Asp5 side chains face in the same direction. These results validates that the NH2+ of Arg1 and the COO− of Asp5 interact electrostatically with the SiO− and SiOH2+ on the SiO2 surface, respectively.

    • Yu Suzuki
    •  & Heisaburo Shindo

  • Original Article |

    Amyloid ß-protein (Aß) is converted to toxic forms through interactions with the ganglioside in neuronal membranes. The highly ganglioside-enriched microdomain (ganglioside cluster) in neuronal membranes plays a key role in Aß assembly. In the present study, lipid components of synaptosome extracted from mouse aged brain was determined by LC-MS spectroscopy. We demonstrated that ganglioside ratio (GM3 to GM1) and cholesterol content are an important factor for inducing Aß assembly. These results provides important insight into the mechanism of polypeptide assembly on the neuronal membrane in Alzheimer’s disease patients.

    • Teruhiko Matsubara
    • , Takahiro Kojima
    •  & Toshinori Sato

  • Original Article |

    Glycosylated double-hydrophilic block copolymers composed of polyacrylamide bearing maltose moieties and poly(N-isopropylacrylamide) were synthesized by a RAFT polymerization technique. The resulting glycosylated block copolymer aggregated, interacted strongly with the lectin Con A, and formed a precipitate in aqueous media above the LCST. The precipitate dissociated into the aqueous medium below the LCST. This behavior of the block copolymer in aqueous media is reversible in response to changes in temperature.

    • Tomonari Tanaka
    •  & Masaru Okamoto

  • Original Article |

    Functional oligochitosan-nanosilica (OCS/nSiO2) hybrid material is likely to be considered as natural vaccine for the growth and disease resistance of the plants. Study on hybrid material from low-cost and waste products such as OCS from chitosan and chitin, and nSiO2 from rice husk is likely to create a novel material with special synergistic effect. The plants treated with OCS/nSiO2 were not completely diseased by Colletotrichum sp. The biomass, the length, the chlorophyll content of the plants treated with OCS, nSiO2 or OCS/nSiO2 were higher than those of the control plants.

    • Ngoc Thuy Nguyen
    • , Dai Hai Nguyen
    •  & Dong Quy Hoang

  • Original Article |

    The adsorption approach is considered as the most effective method of removing dyes from effluents, which among new synthetic materials become high-profile as adsorbents in recent years. This work provides a noble synergistic hydrogel beads based on oxidized corn starch (OCS) and gelatin (G). The OCS and G can form three-dimensionally cross-linked networks owing to Schiff’s base formation. This work also proved that the form of hydrogel beads can be implemented in the synergistic materials for removing dyes from effluents, which has so far been neglected in the literature.

    • Rui Dai
    • , Meng Wai Woo
    •  & Zhihua Shan

  • Invited Review |

    We demonstrate a new methodology of DNA and RNA functionalization with a base surrogate prepared from d-threoninol. With this surrogate, we can introduce functional molecules at any position in the sequence. Our methodology is conceptually similar to copolymerization; phosphoramidite monomers of base surrogates, and natural nucleotides are ‘copolymerized’ on solid supports to prepare functional oligonucleotides. The incorporation of intercalating moieties allows for the design of four stable functional motifs: wedges, interstrand-wedges, dimers and clusters. By selecting suitable functional molecules and motifs, we can design novel photofunctional oligonucleotides.

    • Hiroyuki Asanuma
    • , Keiji Murayama
    •  & Hiromu Kashida

  • Original Article |

    A green method for the synthesis of ‘artificial urushi’ has been developed using cardanol, a main ingredient of cashew nutshell liquid, as the monomer via a reaction mimicking that of natural urushi. A water-in-cardanol (w/o) emulsion was developed by identifying a novel emulsifier, and polymerization of the cardanol emulsion generated prepolymer films, leading to polycardanol (artificial urushi) after curing with mechanical properties that are approximate to those of natural urushi coatings.

    • Takumi Otsuka
    • , Shun-ichi Fujikawa
    •  & Shiro Kobayashi

  • Focus Review |

    This review focuses on the factors that determine the molecular weight of polyhydroxyalkanoate (PHA), an aliphatic polyester synthesized by bacteria for carbon and energy storage. Because the mechanical strength of PHA increases with its molecular weight, high-molecular weight PHA polymers are preferred. The synthesis of high-molecular weight PHA should consider the following factors: the concentration of PHA synthase, occurrence of chain transfer reaction, catalytic activity of PHA synthase and simultaneous degradation of PHA during biosynthesis. These factors have a direct impact on the molecular weight of PHA.

    • Takeharu Tsuge

  • Focus Review |

    Vibrational circular dichroism (VCD) is effective for analyzing the configuration and conformation of various bio(macro)molecules. In addition to a conventional VCD approach using theoretical calculations, this review explains how the use of an exciton-type VCD couplet can be employed to elucidate the structures of bio(macro)molecules, such as carbohydrates, glycerophospholipids, proteins and polyesters.

    • Tohru Taniguchi
    • , Takahiro Hongen
    •  & Kenji Monde

  • Original Article
    | Open Access

    This is the first report on exopeptidase-catalyzed oligopeptide synthesis. Oligo(l-leucine) was synthesized using the exopeptidase carboxypeptidase Y while preventing enzymatic hydrolysis. A high yield of the polypeptide with a narrow polydispersity was successfully obtained by limiting polypeptide cleavage during aminolysis.

    • Sachiko Nitta
    • , Ayaka Komatsu
    •  & Keiji Numata

  • Focus Review |

    In this focus review, we overview our recent works on acyclic artificial nucleic acids (XNAs). Three acyclic XNAs, D-aTNA, SNA and L-aTNA have been developed. D-aTNA can form extremely stable homo-duplex, whereas it shows a high orthogonality with natural nucleic acids. SNA oligomers can change their helicity and chirality depending on sequences. L-aTNA can form stable duplexes with both DNA and RNA. Owing to unique properties of these XNAs, they should find application as tools in biology, biotechnology and nanotechnology.

    • Hiromu Kashida
    • , Keiji Murayama
    •  & Hiroyuki Asanuma

Browse broader subjects

Browse narrower subjects

Browse Biochemistry across other nature.com journals