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11.
Two component water-soluble random copolypeptides consisting of N-hydroxyethyl L-glutamine and hydrophobic L-amino acids such as L-alanine, L-leucine, L-phenylalanine, or L-valine, were prepared by carrying out aminolysis reactions with 2-amino-1-ethanol (E) on starting copolymers consisting of γ-benzyl L-glutamate (B) and the corresponding hydrophobic L-amino acid. The effects of copolymer composition and sequential distributions, as well as molecular conformations, on the rate of degradation by bromelain in a PECF at pH 7.4 and 37.0°C to simulate in vivo polymer degradation. All the samples were found to be extensively degraded by random chain fracture with bromelain. Further, the degradation data for these samples followed the Michaelis-Menten rate law, being of the first order in papain concentration. The nature of side chains and the molecular conformations are important to the rate of degradation by bromelain. 相似文献
12.
Shibata M Matsumoto K Hikino Y Oe M Ojima K Nakajima I Muroya S Chikuni K 《Meat science》2011,89(4):451-456
This study investigated the growth performance and gene expression for muscle development between grass hay-fed (GH) and concentrate-fed (CT) steers. Daily gain and energy intake during the fattening period of the GH group were lower than those of the CT group. Analysis of C/EBPα, PPARγ2, myosin heavy chain (MHC), and myostatin gene expressions was performed by real-time PCR. Expressions of C/EBPα and myostatin in semitendinosus and longissimus lumborum (LL) muscles were higher in the CT group than in the GH group at the end of fattening. In LL muscle, MHC expression at the end of fattening was greater in the GH group than in the CT group. These results suggest that regulation of adipogenesis and myogenesis by the expression of genes involved in muscle development might have occurred in the skeletal muscle of the GH group by the feeding of grass hay and/or because of the low energy intakes. 相似文献
13.
Takuji KawamuraMasahiro Misaki Yasuko KoshibaSatoshi Horie Kenji KinashiKenji Ishida Yasukiyo Ueda 《Thin solid films》2011,519(7):2247-2250
The detailed structure of crystalline β-phase poly(9,9-dioctylfluorene) (PFO) films was studied by polarized optical measurements, transmission electron microscopy, and grazing-incidence X-ray diffraction. Crystalline β-phase PFO thin films were fabricated by a friction transfer technique and subsequent vapor treatment. Compared to the α-phase, the lattice parameters of the β-phase crystals shrank along the a-axis (film thickness direction) and elongated along the b-axis (side-chain direction), but the period along the c-axis (main-chain direction) remained nearly equal. These changes in molecular packing were consistent with a planar conformational change from the α-phase to the β-phase of PFO. 相似文献
14.
15.
Hosomi N Kawamura-Konishi Y Kawano R Fujii I Suzuki H 《Journal of Bioscience and Bioengineering》2005,99(3):222-229
Monoclonal antibody 2D7 generated against a transition-state analog N-methyl mesoporphyrin catalyzes a reaction for insertion of a cupric ion into mesoporphyrin. To investigate amino acid residues responsible for the catalytic activity, site-directed mutagenesis of the amino acid residues in the third complementarity determining region of the heavy chain (CDRH3) was performed on the antigen-binding fragment (Fab) of the antibody. Recombinant Fab mutants, in which Arg95 is replaced with Ala (R95A), Asp96 with Asn (D96N) and Met97 with Gly (M97G), were examined in terms of the catalytic efficiency of the reaction (k/K(S)) and the dissociation constant for N-methyl mesoporphyrin binding (K(d)) and these values were compared with those of the wild type. The k/K(S) values of the R95A and D96N mutants were 0.96% and 1.0% of that of the wild type, respectively, whereas the M97G mutant had no detectable catalytic activity. The K(d) values of the R95A and D96N mutants were 165 and 69 times that of the wild type, respectively, while that of the M97G mutant was similar to that of the wild type. The relationship between the k/K(S) and 1/K(d) values in the wild type and the R95A and D96N mutants suggests that Arg95 and Asp96 are responsible for stabilizing the transition-state in the catalytic reaction. The results of the M97G mutant allow us to propose that Met97 plays an important role in the catalytic activity probably due to a subtle and specific conformation of the antibody. 相似文献
16.
This paper proposes a new synthesis method for methanol as a future alternative fuel, by the combination of carbon supplied from wood and hydrogen supplied from the electrolysis of water using a solar power generation system in the desert. In the developed countries, more than half of the potential forest area has already been converted into other land uses, while existing forests are well organized and available for wood production. In the developing countries, potential forest sites are expected to be available for wood production, even though they are presently grasslands or secondary forests, while natural tropical forests will not be allowed to be converted into artificial forests. The area available for plantations within 500 km distant from deserts was estimated to be 65 Mha in the world, except for the mountain areas. Biomass production from these sites will be converted annually into 980 Mt methanol with hydrogen from the deserts. This amount is equal to 34% of the world's fuel consumption by vehicles. 相似文献
17.
We describe the development of a new transformation system, using multiple auxotrophic marker genes, for the fission yeast Schizosaccharomyces pombe. We developed three new auxotrophic marker genes (arg12(+), tyr1(+) and ade7(+)) and generated a new host strain, YF043, by Cre-loxP-mediated gene disruption. YF043 possessed six mutated biosynthetic genes (leu1-32, ura4-M190T, arg12::loxP, tyr1::loxP, ade7::loxP and his2::loxP). The combination of this host strain and the new selectable markers can be used for gene disruption using the same preexisting transformation systems. In addition, Sz. pombe vectors were constructed, containing selectable marker genes that complement the auxotrophies of YF043. These new vectors are available for gene disruption and heterologous protein expression in strain YF043. The new Sz. pombe host strain will be a useful tool for molecular genetic studies of Sz. pombe where multiple recombinant modifications or multiple mutations are needed. 相似文献
18.
Kumaki Y Ogawa M Hirano T Yoshikawa K Iwasawa N Yagi T Hakamata W Oku T Nishio T 《Journal of Bioscience and Bioengineering》2011,111(2):134-139
The chromosomal DNA of the syntrophic thermophile Symbiobacterium thermophilum contains open reading frames of the genes encoding family M42 aminopeptidases, Pep1079, Pep1080, and Pep1081. To characterize these peptidases, the genes were cloned into Escherichia coli and overexpressed. Our experiments using the recombinant proteins confirmed that Pep1079, Pep1080, and Pep1081 are components of arginyl or lysinyl aminopeptidases that require Co2+ for enzymatic activity. Coexistence of Pep1079 and Pep1080 is necessary for expressing high peptidase activity. Pep1081 enhances the activity of Pep1079 and Pep1080. 相似文献
19.
Okabe Y Watanabe A Shingu H Kushibiki S Hodate K Ishida M Ikeda S Takeda T 《Meat science》2002,62(4):428-462
Relationships between α-tocopherol concentration in the muscle and development of lipid oxidation or volatiles in raw venison were studied. Fourteen Japanese Shika Deer (Cervus nippon) were fed various amounts (0–3.0 g of α-tocopheryl acetate per animal) during the different periods (0–37 days) and then M. longissimus thoracium et lumborum (LD muscles) with a range of α-tocopherol concentrations (4.1–15.1 mg/kg tissue) were obtained. For stabilizing the lipid during storage for 11 days under air, over ca. 9 mg of α-tocopherol per kg tissue were required based on levels of 2-thiobarbituric acid reacting substances (TBARS) numbers. Nine compounds were identified in headspace volatiles, and one of the volatiles was hexanal which has been recognized as off-flavour component. For depressing the hexanal evolution, at least ca. 9 mg of α-tocopherol per kg tissue were also required for 11 days’ storage. This value was much higher than other species. The reasons for higher requirement of α-tocopherol were possibly due to the higher concentration of unsaturated fatty acid and myoglobin in venison. 相似文献
20.
Hisatsune K Shiraishi T Takuma Y Tanaka Y Luciano RH 《Journal of materials science. Materials in medicine》2007,18(4):577-581
Age-hardening behavior during continuous heating in commercial dental casting gold alloys was investigated by means of electrical
resistivity measurements, hardness tests and X-ray diffraction. Two distinguishable behaviors were detected. It is considered
that the difference was attributed to the amount of platinum, and the atomic ratio of gold and copper in each alloy. The phase
transformations during continuous heating progressed into two steps (stages I and II). Increase of the platinum addition in
gold-based alloys retards the rate of the reaction and decreases remarkably the amount of stage I. 相似文献