Effects of enzymatic deamidation by protein-glutaminase on structure and functional properties of wheat gluten

Protein-glutaminase (PG) purified from Chryseobacterium proteolyticum was used to investigate its deamidation effects on wheat gluten. Water-insoluble gluten was able to be deamidated to the extent of deamidation degree (DD) 72% in 200 mM sodium phosphate buffer (pH 7) at 40 degrees C for 30 h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis exhibited an upper shift of gluten bands with only deamidation for 1.5-2.0 h (DD 35-45%) compared to the bands of nondeamidated gluten. Results of Fourier transform infrared analysis revealed alterations in secondary structure of gluten by PG deamidation. The assignment within amide I region showed decreases in both inter- (around 1695 cm(-1)) and intramolecular beta-sheets (around 1680 cm(-1)) by deamidation suggesting the deterioration of the aggregation ability of gluten molecules. Solubility and emulsification properties of gluten at pH 7 were improved by deamidation, while both properties at pH 3 were deteriorated by deamidation. Enzyme-linked immunosorbent assay identified that allergenicity of deamidated gluten as compared to the nondeamidated cohorts was decreased remarkably as the deamidation time was prolonged.     

Effects of Ca2+ and sulfhydryl reductant on the polymerization of soybean glycinin catalyzed by mammalian and microbial transglutaminases

Two types of transglutaminases (TGases), Ca(2+)-dependent TGase derived from guinea pig liver (GTGase) and Ca(2+)-independent TGase derived from a variant of Streptoverticillium mobaraense (MTGase), were used to study the cross-linking of soybean 11S globulin (glycinin). The effects of sulfhydryl reductant (dithiothreitol, DTT) and Ca(2+) on the conformation and TGase-catalyzed polymerization of glycinin were investigated. The conformational change of glycinin was probed by spectral methods. The degree of cross-linking and the polymer (aggregate) formation were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and dynamic light scattering, respectively. Addition of DTT stimulated the TGase-catalyzed cross-linking reactions without destroying the secondary and tertiary structure of glycinin but did not influence the polymer or aggregate formation. It was found that Ca(2+) caused the formation of larger size polymers at lower concentrations, while it suppressed the polymerization at higher concentrations. In addition, the cross-linking behaviors of glycinin were shown to be different between MTGase- and GTGase-catalyzed systems.     

Growth, Net Photosynthetic Rate, Nutrient Status and Secondary Xylem Anatomical Characteristics of Fagus Crenata Seedlings Grown in Brown Forest Soil Acidified with H2SO4 Solution

Dry matter production, net photosynthetic rate, leaf nutrient status and trunk anatomical characteristics of Fagus crenata seedlings grown in brown forest soil acidified by adding H₂SO₄ solution were investigated. The soil acidification leaded to decreased (Ca+Mg+K)/Al molar ratio in the soil solution. Dry mass per plant of the seedlings grown in the soil treated with H⁺ at 120 mg·L^?1 was significantly reduced compared with the control value at 0 mg·L^?1. When net photosynthetic rate was reduced in the seedlings grown in the soil treated with H⁺ at 120 mg·L^?1, the carboxylation efficiency and maximum net photosynthetic rate at saturated CO₂-concentration were lower than the control values. The addition of H⁺ to the soil at 120 mg·L^?1iinduced a reduction in the concentration of Ca in the leaf. By contrast, the concentration of Al in the leaf was increased with increasing the amount of H⁺ added to the soil. The annual ring formed in the seedlings grown in the soil treated with H⁺ at 120 mg·L^?1 was significantly narrower than that at 0 (control), 10, 30, 60 or 90 mg·L^?1. Based on the results obtained in the present study, we conclude that Fagus crenata is relatively sensitive to a reduction in the (Ca+Mg+K)/Al molar ratio of soil solution compared with Picea abies.     

Within-stem variations in mechanical properties of <Emphasis Type="Italic">Melia azedarach</Emphasis> planted in northern Vietnam

Within-stem variations in the mechanical properties of 17–19-year-old Melia azedarach planted in two sites in northern Vietnam were examined by destructive and nondestructive methods. Wood samples were collected from 10, 50, and 90% of the radial length from pith on both sides (North and South) at 0.3, 1.3, 3.3, 5.3, and 7.3 m heights above the ground. The mean values in whole trees of wood density (WD), modulus of rupture (MOR), modulus of elasticity (MOE), and dynamic modulus of elasticity (E_d) at 12% moisture content were 0.51 g/cm³, 78.58 MPa, 9.26 GPa, and 10.93 GPa, respectively. Within the stem, the radial position was a highly (p?<?0.001) significant source of variation in mechanical properties. MOR, MOE, and E_d increased from pith to bark. WD had a strong positive linear relationship with both MOR (r?=?0.85, p?<?0.001) and MOE (r?=?0.73, p?<?0.001). This suggests that it is potentially possible to improve mechanical properties through controlling WD. MOR had also a strong linear relationship with E_d (r?=?0.84, p?<?0.001). This indicates that E_d is a good indicator to predicting the strength of wood if the density of measured element is known. Besides, the stress wave method used in this study provides relatively accurate information for determining the stiffness of Melia azedarach planted in northern Vietnam.     

Transverse shrinkage variations within tree stems of <Emphasis Type="Italic">Melia azedarach</Emphasis> planted in northern Vietnam

This study quantified variations within tree stems in tangential shrinkage (α_T), radial shrinkage (α_R), and tangential/radial shrinkage ratio (α_T/α_R) of Melia azedarach grown in two different sites in northern Vietnam. The overall values of α_T, α_R, and α_T/α_R were 7.05%, 4.38%, and 1.64, respectively. The variation pattern in α_T and α_R was found to increase gradually from pith to bark and this trend was similar on both sites. In radial direction, the α_T/α_R decreased significantly from 10 to 50% of the radial length from pith before approaching a constant value toward the outside. The transverse shrinkage variation with height was very small and without statistical significance. There were strong positive relationships between transverse shrinkage and basic density (BD). This implies that the selection for high wood density may lead to increase wood transverse shrinkage. In addition, the α_T and α_R had significant positive linear relationships with both acoustic wave velocity (V_L) and dynamic modulus of elasticity of log (DMOE_log). This result suggests that it might be possible to sort lumber with large transverse shrinkage by stress wave method for M. azedarach planted in northern Vietnam.     

Analysis of concrete strength effective factors of diagonal strutmechanism on frame exterior beam-column joints

This paper uses the strut-truss model to analyze the shear strength of reinforced concrete frame exterior joints through thirty-five shear failure type joints without beam flexural yield and six shear failure joints after beam flexural yield.It discusses the influence of parameters including concrete compressive strength,column axial-compression ratio,amount of joint horizontal or vertical hoop,and angle of strut mechanism etc.,on concrete strength effective factor ρ of diagonal strut mechanism.The analysis results show that ρ value deterioration ratio at peak load increases with the increase od concrete strength.The effect of joint hoop on ρ value deterioration is more significant using ordinary strength concrete than the case using high strength concrete.The contribution of strut mechanism to joint shear force is more than 80% when joint shear reinforcement ration is less than 0.3%.The joint strength equation is proposed based on the analysis results of the factor ρ,and the calculated values agree well with the experimental results.     

Development of SNP markers for individual identification and parentage test in a Japanese Black cattle population

This study describes the development of efficient single nucleotide polymorphism (SNP) markers for individual identification and parentage tests in a Japanese Black cattle population. An amplified fragment length polymorphism method was employed to detect informative candidate markers, and yielded 44 SNP markers from 220 primer combinations. 29 unlinked SNPs were finally selected as diagnostic markers. The allelic frequencies for each marker were estimated by using PCR‐RFLP in the Japanese Black population. Based on the frequency data, the estimated identity power of these markers was 2.73 × 10^?12. Parentage exclusion probabilities, when both suspected parents' genotypes were known and when only one suspected parent was genotyped, were estimated as 0.96929 and 0.99693, respectively. This panel of SNP markers is theoretically sufficient for individual identification, and would also be a powerful tool for a parentage test in Japanese Black cattle. The markers could contribute to the management of the beef industry in Japan.     

Effect of simulated acid fog on membrane-bound calcium (mCa) in fir (Abies firma) and cedar (Cryptomeria japonica) mesophyll cells

The decline of virgin fir (Abies firma) forest at Mt. Oyama has been reported. Related field observations suggest that high acidity fog is linked with its decline. However, cedar (Cryptomeria japonica) in the same area shows no symptoms of decline. For assessing effects of acid fog on membrane-bound calcium (mCa) of the leaf mesophyll cells, 9-year-old seedlings of fir (Abies firma) and 8-year-old seedlings of cedar (Cryptomeria japonica) were exposed twice a week to simulated acid fog (SAF at pH 3 with pH 5 as control) for 2 h per day in a chamber during May–December 2007 (except August). Current and 1-year-old needles were collected from seedlings and analyzed at 1-month intervals. For current-year needles of fir, mCa levels in cells exposed to SAF at pH 3 were significantly lower than in cells exposed to pH 5, especially during September 2007–March 2008. In contrast, it is noteworthy that mCa levels of cedar were maintained as virtually constant irrespective of SAF acidity, indicating that fir is more sensitive to acid fog than is cedar. Based on these results, mCa loss by acid fog might also be caused in the declining virgin fir forest at Mt. Oyama.