Bovine Serum Albumin Nanoparticle Promotes the Stability of Quercetin in Simulated Intestinal Fluid

2011 ◽  
Vol 59 (11) ◽  
pp. 6292-6298 ◽  
Author(s):  
Ru Fang ◽  
Ruifang Hao ◽  
Xia Wu ◽  
Qi Li ◽  
Xiaojing Leng ◽  
...  
2020 ◽  
Vol 106 ◽  
pp. 105892 ◽  
Author(s):  
Xuanting Liu ◽  
Jingbo Liu ◽  
Wenqi Zhang ◽  
Robin Pearce ◽  
Meiru Chen ◽  
...  

1978 ◽  
Vol 5 (5) ◽  
pp. 571 ◽  
Author(s):  
MD Hatch ◽  
IR Oliver

The stability of phosphoenolpyruvate carboxylase (EC 4.1.1.31) was examined following extraction of the enzyme from leaves of several C4 plants. Extracts were rapidly processed on small Sephadex G-25 columns to free protein of small-molecular-weight compounds. With most of the species examined, activity was rapidly lost at both 0 and 25°C when the pH was about 7.8 or higher. Addition of bovine serum albumin to extracts incubated at 25°C and pH 8.2 not only prevented inactivation with several species, but resulted in a substantial increase in activity. The addition of dithiothreitol plus Mg2+ to extracts from some of these species reduced or prevented inactivation. With extracts maintained at 0°C, addition of either bovine serum albumin or dithiothreitol was effective only in reducing the rate of inactivation in extracts. Phosphoenolpyruvate carboxylase activity remained stable, or increased substantially, when extracts buffered between pH 7.4 and 6.9 were incubated at either 0 or 25°C. Activation was usually complete within an hour and was often significantly greater at 25°C or when bovine serum albumin was added. The activity of partially purified phosphoenolpyruvate carboxylase from Zea mays was similarly affected by pH, temperature, and bovine serum albumin. The present studies raise doubts about the accuracy of phosphoenolpyruvate carboxylase determinations made during the course of some previous studies on C4 species. Reliable procedures for the determination of phosphoenolpyruvate carboxylase activity in C4 plant extracts are described. Possible physiological implications of the results are considered.


2012 ◽  
Vol 8 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Shigehiko Takegami ◽  
Shoko Uchida ◽  
Eriko Aoi ◽  
Takumi Yamamoto ◽  
Aki Yasuhara ◽  
...  

1991 ◽  
Vol 14 (4) ◽  
pp. 336-341 ◽  
Author(s):  
Chong-Kook Kim ◽  
Han-Sung Kim ◽  
Beum-Jin Lee ◽  
Jeong-Hee Han

1979 ◽  
Vol 25 (5) ◽  
pp. 659-664 ◽  
Author(s):  
E J Sampson ◽  
S S McKneally ◽  
V S Whitner ◽  
C A Burtis ◽  
D D Bayse

Abstract Eight different pools of purified human mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase were prepared, to examine the effects of the following matrix variables: the matrix support material (bovine serum albumin and polyvinylpyrrolidone), endogenous pyridoxal concentration, and azide as an antimicrobial preservation. Storage temperatures of 25 and 37 degrees C were used as a rapid and convenient means of accelerating the degradation process. Activity of the enzyme was measured with and without pyridoxal in the reaction solution. We found that the mitochondrial isoenzyme was consistently more labile than the cytoplasmic isoenzyme under identical storage conditions. Both isoenzymes were more stable in matrixes containing bovine serum albumin than in those containing polyvinylpyrrolidone. No apparent difference in the stability of either isoenzyme was observed at matrix pyridoxal concentrations of 15 micromol/L and 150 micromol/L. Only the mitochondrial isoenzyme in matrixes containing bovine serum albumin and 15 micromol of pyridoxal per liter had increased activity (about 9%) when pyridoxal was added to the enzymatic reagent. The amount of activity in reconstituted specimens did not apparently change after 72 h at 4 degrees C.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
Kirsten Ullmann ◽  
Gero Leneweit ◽  
Hermann Nirschl

This research highlights the capacity of a newly introduced centrifugation process to form liposomes from water-in-fluorocarbon nano-emulsions stabilized with phospholipids to incorporate macromolecular and sensitive active pharmaceutical ingredients (API). The encapsulation efficiency of the produced liposomes, incorporating fluorescein-sodium, bovine serum albumin and fluorecein isothiocyanate dextran as model APIs, is determined by applying Vivaspin® centrifugation filtration and quantified by UV-Vis spectroscopy. It was found that higher densities of the fluorocarbons used as the hydrophobic phase enable a higher encapsulation efficiency and that an efficiency of up to 98% is possible depending on the used phospholipid. Among the engineering aspects of the process, a comparison between different membrane substances was performed. Efficiency increases with a higher phospholipid concentration but decreases with the addition of cholesterol. Due to the higher bending modulus, liposome formation is slowed down by cholesterol during liposome closure leading to a greater leakage of the model API. The encapsulation of bovine serum albumin and dextran, both investigated under different osmotic conditions, shows that an efflux negatively affects the encapsulation efficiency while an influx increases the stability. Overall, the process shows the potential for a very high encapsulation efficiency for macromolecules and future pharmaceutical applications.


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