关键词：
late indica rice;rice bran rancidity;copper soap method;partial least squares regression (PLS)
摘要：
Rice bran lipase Activity (RBLA) is one of the important parameters to affect the rice bran rancidity. The activity of rice bran during 0-12 h after milling off from a kind of late indica brown rice, at 25-30 degrees C, were determined by copper soap method and near-infrared spectroscopy (LAIRS), respectively. Among the RBLA prediction models established by principal component regression (PCR) and partial least squares regression (PLS), the best model was treated by PLS coupled with second derivative, the correlation coefficient between predicted value and chemical value was 0.9911, root square standard error (RMSEC) was 0.658, root mean square error of prediction was 3.03.
关键词：
DEAMIDATION;GLUTAMINASES;GLUTELINS;HYDROLASES;MODIFICATION;PH;PROTEINS CEREAL;RICE;SOLUBILITY;STRUCTURE;Catering;speciality and multi-component foods;Protein isolates
摘要：
The effects of glutaminase on deamidation of rice glutelin were investigated. Water-insoluble rice glutelin was deamidated to the extent of deamidation degree 52.29% in 200 mmol/L sodium phosphate buffer (pH 7.0) at 37 degrees C for 48 h. Zeta potential analysis indicated that the glutamines of rice glutelin were deamidated into glutamic residues. Size exclusion chromatography results demonstrated that glutaminase deamidation broke the hydrophobic, hydrogen and some intermolecular disulfide bonds in rice glutelin and thereby rearranged the molecular weight distributions without serious cleavage of the peptide bonds. Fourier transform infrared analysis revealed the transformation of alpha-helix to random coil and beta-turn by deamidation and suggested that deamidated rice glutelin maintained more flexible or extended forms. Solubility properties of rice glutelin in mildly acid (pH 5) and neutral buffers (pH 7) were remarkably improved by glutaminase deamidation. These new features of deamidated rice glutelin suggested that glutaminase could be a potential tool for enhancing the usability of rice protein in the food industry. (C) 2011 Elsevier Ltd. All rights reserved.
摘要：
In this paper, we investigated three ligand systems, symmetric and asymmetric pyridyl-containing tridentate ligands (L1NH2 = (bis(2-pyridylmethyl)-amino)-ethylamine, L2H = (bis(2-pyridylmethyl)-amino)-acetic acid, L3NH2 = [(6-amino-hexyl)-pyridyl-2-methyl-amino]-acetic acid) as bifunctional chelating agents for labeling biomolecules. These ligands reacted with the precursor fac-[188Re(CO)3(H2O)3]+ and yielded the radioactive complexes fac-[188Re(CO)3L] (L = three ligands), which were identified by RP-HPLC. The corresponding stable rhenium tricarbonyl complexes (1–3) were allowed for macroscopic identification of the radiochemical compounds. 188Re tricarbonyl complexes, with log Po/w values ranging from −1.36 to −0.32, were obtained with yields of ≥90% using ligand concentrations within the 10−6−10−4M range. Challenge studies with cysteine and histidine revealed the high stability properties of these radioactive complexes, and biodistribution studies in normal mice indicated a fast rate of blood clearance and high rate of total radioactivity excretion, primarily through the renal-urinary pathway. In summary, these asymmetric and symmetric pyridyl-containing tridentate ligands are potent bifunctional chelators for the future biomolecules labeling of fac-[188Re(CO)3(H2O)3]+.
摘要：
The purpose of this work was to indirect label IgG with fac-[188Re(CO)3(H2O)3]+ and to check the radiochemical behavior of the labeled product. The compound of (bis(2-pyridylmethyl)-amino)-acetic acid (L2H) was synthesized and labeled with fac-[188Re(CO)3(H2O)3]+. The labeling yield of 188Re(CO)3–L2H was more than 90%. The effects of protein concentration, reaction time, pH and reaction temperature of labeling of IgG with 188Re(CO)3–L2H were investigated. The conjugation conditions were optimized. The labeled product was analyzed by size exclusion HPLC and TLC. The stability of 188Re(CO)3–L2H–IgG in vitro was high. The results of this study may be useful for [188Re(CO)3(H2O)3]+ labeling of protein for radioimmunotherapy.
