2P069 ジスルフィド結合を導入することによって高度に安定化した低温ショック相同蛋白質の熱力学的評価(蛋白質(物性(安定性、折れ畳みなど)),口頭発表,第45回日本生物物理学会年会)

3P075 分子モーターSecAのアロステリーと天然トポロジーの関係(蛋白質(物性(安定性、折れ畳みなど)),口頭発表,第45回日本生物物理学会年会)

Genually Inst Mo ek Uare Mjkrobio ogic und Blo hnol ie WWUM uun

3P073 回転拡散運動からみたタンパク質間相互作用 : ポリエチレングリコールの効果(蛋白質(物性(安定性、折れ畳みなど)),口頭発表,第45回日本生物物理学会年会)

Dissimilarity in the Reductive Unfolding Pathways of Two Ribonuclease Homologues

Thiolated pectin-doxorubicin conjugates: Synthesis, characterization and anticancer activity studies.

The effects of polyphenol removal from common buckwheat seed flours with cold aqueous organic solvents (including 95% ethanol, 70% 2-propanol, and 80% methanol, v/v) on the physicochemical and conformational properties of their protein isolates (BPI) were investigated. The extraction resulted in considerable reduction in its polyphenol content, especially protein-bound polyphenol content, and concomitant increase in its protein content. The efficiency of the removal of the polyphenols was much better in the 2-propanol case than in other two cases. The surface hydrophobicity of the proteins changed slightly, while the disulfide bond contents remarkably increased, partially at the expense of free sulfhydryl group contents. The protein solubility in the pH range of 7.0-11.0 and the proportion of undenatured globulins in BPI products were variably improved by the organic solvent extraction, and the extent of the improvements was highest in the 2-propanol case. Intrinsic emission fluorescence and far-UV and/or near-UV CD spectra showed that polyphenol removal resulted in significant changes in tertiary and/or secondary conformations of the proteins in BPI, and the changes were also related to the efficiency of the removal of the polyphenols. These results suggest that the physicochemical and conformational properties of BPI are closely related to its polyphenol level, and there is also a close relationship between its physicochemical properties and tertiary and/or secondary conformations.

Physicochemical and structural properties of lunasin revealed by spectroscopic, chromatographic and molecular dynamics approaches

Effects of high pressure on the physicochemical and functional properties of peanut protein isolates

Ultrasound-induced yield increase of yuba (protein-lipid film from soybean milk) and changes in structural, physicochemical, and digestive properties during film-peeling process

Scorpion toxins are miniglobular proteins containing a common structural motif formed by an alpha-helix on one face, an antiparallel beta-sheet on the opposite face, and three disulfide bonds making up most of its internal volume. We have investigated the role of these evolutionary conserved bonds by replacing each couple of bridged cysteine residues of the scorpion charybdotoxin by a pair of nonbridging L-alpha-aminobutyric acid (Aba) residues. Three analogues were obtained by solid-phase synthesis, Chab I, Chab II, and Chab III, containing the Aba residues in positions 7 and 28, 13 and 33, 17 and 35, respectively. Circular dichroism analysis showed that the purified Chab II acquired a conformation similar to that of charybdotoxin, while the Chab I and Chab III possess decreased nativelike characteristics. All analogues block single high-conductance Ca(2+)-activated K+ channels from rat skeletal muscle inserted into planar lipid bilayers, but with different potencies. Chab II is the most active analogue (KD = 8.0 x 10(-8) M), with a 9-fold lower affinity as compared to native charybdotoxin. Chab I and Chab III have, respectively, 180- and 580-fold lower affinity. Therefore, the removal of evolutionary conserved disulfide bridges does not prevent the toxin to adopt a functional and presumably nativelike structure. However, removal of one disulfide bond affects the yields of formation of correct pairing between the remaining cysteine residues, and only Chab I preserves the ability to form the native disulfide pairings with high efficiency. This is the only analogue to preserve particular spacings of three and one residue between the cysteines, which have been described to thermodynamically disfavor disulfide bond formation between the cysteines [Zhang R., and Snyder, G. H. (1989) J. Biol. Chem. 264, 18472-18479]. Therefore, we conclude that the position of the cysteine residues in the sequence of charybdotoxin, by disfavoring specific pairings and favoring others, may govern selective formation of specific disulfide bonds, thus, explaining the efficient folding properties of Chab I and of native charybdotoxin. The structural properties of the Chab analogues and the discovered role of the cysteine spacings have interesting implications in protein design and engineering.

Effects of NaOH/NaCl pickling on heat-induced gelation behaviour of egg white

Redox-responsive nanoparticles based on Chondroitin Sulfate and Docetaxel prodrug for tumor targeted delivery of Docetaxel

Binding properties of protein Arp, A bacterial IgA-receptor

Effect of ultrasonic on the structure and quality characteristics of quinoa protein oxidation aggregates

Hydrophobins are small amphipathic proteins conserved in filamentous fungi. In this review, the properties and functions of Aspergillus hydrophobins are comprehensively discussed on the basis of recent findings. Multiple Aspergillus hydrophobins have been identified and categorized in conventional class I and two non-conventional classes. Some Aspergillus hydrophobins can be purified in a water phase without organic solvents. Class I hydrophobins of Aspergilli self-assemble to form amphipathic membranes. At the air–liquid interface, RolA of Aspergillus oryzae self-assembles via four stages, and its self-assembled films consist of two layers, a rodlet membrane facing air and rod-like structures facing liquid. The self-assembly depends mainly on hydrophobin conformation and solution pH. Cys4–Cys5 and Cys7–Cys8 loops, disulfide bonds, and conserved Cys residues of RodA-like hydrophobins are necessary for self-assembly at the interface and for adsorption to solid surfaces. AfRodA helps Aspergillus fumigatus to evade recognition by the host immune system. RodA-like hydrophobins recruit cutinases to promote the hydrolysis of aliphatic polyesters. This mechanism appears to be conserved in Aspergillus and other filamentous fungi, and may be beneficial for their growth. Aspergilli produce various small secreted proteins (SSPs) including hydrophobins, hydrophobic surface–binding proteins, and effector proteins. Aspergilli may use a wide variety of SSPs to decompose solid polymers.