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Feunai Agape Papalii Tautau Minoru Izumi Emiko Matsunaga Yujiro Higuchi Kaoru Takegawa 《Journal of Applied Glycoscience》2020,67(3):87
α-L-Rhamnosidases (α-L-Rha-ases, EC 3.2.1.40) are glycosyl hydrolases (GHs) that hydrolyze a terminal α-linked L-rhamnose residue from a wide spectrum of substrates such as heteropolysaccharides, glycosylated proteins, and natural flavonoids. As a result, they are considered catalysts of interest for various biotechnological applications. α-L-rhamnose (6-deoxy-L-mannose) is structurally similar to the rare sugar α-L-mannose. Here we have examined whether microbial α-L-Rha-ases possess α-L-mannosidase activity by synthesizing the substrate 4-nitrophenyl α-L-mannopyranoside. Four α-L-Rha-ases from GH78 and GH106 families were expressed and purified from Escherichia coli cells. All four enzymes exhibited both α-L-rhamnosyl-hydrolyzing activity and weak α-L-mannosyl-hydrolyzing activity. SpRhaM, a GH106 family α-L-Rha-ase from Sphingomonas paucimobilis FP2001, was found to have relatively higher α-L-mannosidase activity as compared with three GH78 α-L-Rha-ases. The α-L-mannosidase activity of SpRhaM showed pH dependence, with highest activity observed at pH 7.0. In summary, we have shown that α-L-Rha-ases also have α-L-mannosidase activity. Our findings will be useful in the identification and structural determination of α-L-mannose-containing polysaccharides from natural sources for use in the pharmaceutical and food industries. 相似文献
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E De Vecchi MG Pala G Di Credico V Agape G Paolini PA Bonini A Grossi R Paroni 《Canadian Metallurgical Quarterly》1998,79(3):242-247
OBJECTIVE: To determine whether preoperative left ventricular ejection fraction (LVEF) is related to the degree of myocardial oxidative stress during bypass surgery in man. DESIGN: Observational study. SETTING: Tertiary care centre. PATIENTS AND INTERVENTIONS: 31 patients (LVEF range was 20% to 68%) undergoing elective coronary bypass surgery with blood cardioplegic reperfusion were studied. Arterial and coronary sinus blood was collected before aortic cross clamping (T0) and at 0 (T1), 15 (T2), and 30 (T3) minutes after unclamping. Transmural left ventricular biopsies were also obtained from 15 patients at T0 and at T1. MAIN OUTCOME MEASURES: Glutathione and adenine nucleotides were measured in myocardial biopsies, while coronary sinus-artery differences for glutathione, nucleotides, and products of lipid peroxidation were calculated from blood specimens. Creatine kinase (myocardial band; CK-MB) was measured in plasma at four and 12 hours after operation. RESULTS: Myocardial glutathione and adenine nucleotides were correlated (p < 0.02) with preoperative LVEF both at T0 (r = 0.909 and 0.672) and T1 (r = 0.603 and 0.605). Oxidised glutathione released from the heart during reperfusion was inversely correlated with LVEF (r = -0.448, -0.466, and -0461 at T1, T2, and T3, p < 0.01), while reduced glutathione (r = 0.519 and 0.640 at T1 and T2) and glutathione redox ratio (r = 0.647, 0.714, 0.645, and 0.702 at T0, T1, T2, and T3) showed a direct correlation (p < 0.01). Lipid peroxidation at T1 was negatively related to LVEF (r = -0.492). CK-MB was also negatively related to LVEF (r = -0.440 at 4 h and -0.462 at 12 h). CONCLUSIONS: The capacity to counterbalance oxidative burst following ischaemia and reperfusion appears to be related to the functional ability of the heart. 相似文献
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Andrea Mosca Assunta Carpinelli Rita Majavacca Angelo Cantu'-Rajnoldi Massimo Garatti Renata Paleari Maurizio Ferrari Vittorio Agape Liliana Maccioni Sandra Pisano Renzo Galanello 《Journal of Automated Methods and Management in Chemistry》1989,11(6):273-279
The authors describe a modification of the instrumental parameters
of the Diamat fully automated HPLC system for Hb A2 assay
(Bio-Rad Laboratories, Milan, Italy) in order to obtain
simultaneous determination of Hb A2 and Hb F.Hb A2 and Hb F measurements are reproducible (within-run CV
2.6%, with Hb A22.7%; 5.1%, with Hb F 1.3%) and accurate
(from a comparison with two microchromatographic techniques for
Hb A2: r = 0.9639 and 0.9755; with two alkali denaturation
procedures for Hb F: r = 0.9990 and 0.9952; with radial
immunodiffusion, r = 0.9877). Assay linearity has been confirmed
for Hb A2 concentrations between 0 and 6.0%, and for Hb F
between 0 and 60%. The data obtained from the analysis of some
pathological samples for Hb Bart''s, Hb H, Hb J Sardegna, Hb
Lepore and Hb S are in agreement with cellulose acetate
electrophoresis analysis.The Hb A2 reference intervals for normals (N = 597) and
Beta-thalassemia carriers (N = 200) are respectively (95%
limits) 2.02-3.27 and 3.92-5.90 in % units. Hb F values
measured in normals (N = 968), in β-thal carriers (N = 302) and
in δβ-thal carriers (N =3) have been found to be consistent with
the usual diagnostic parameters.Some minor limitations emerged: the most relevant concerns Hb
A1c, which is overestimated with respect to a reference method (y =
1.217x + 0.16; N = 79; r = 0.9235). A probable interference
from labile fractions is responsible for this Hb A1c inaccuracy. 相似文献
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