scholarly journals Inhibition of glucose 6-phosphatase by pure and impure C-type phospholipases. Reactivation by phospholipid dispersions and protection by serum albumin

1975 ◽  
Vol 148 (2) ◽  
pp. 279-294 ◽  
Author(s):  
B R Cater ◽  
P Trivedi ◽  
T Hallinan
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Phospholipase C ◽  
Phosphatase Activity ◽  
Bovine Serum ◽  
Intact Control ◽  
Total Glucose ◽  
Triton X ◽  
Hydrolysis Of

1. Pure or impure C-type phospholipases hydrolysed rat liver microsomal phosphatides in situ at 5 degrees or 37 degrees C. At 5 degrees C mean hydrolysis of total phospholipids was 90% by Bacillus cereus and 75% by Clostridium perfringens (Clostridium welchii) C-type phospholipases. 2. Four degrees of inhibition of glucose 6-phosphatase (D-glucose 6-phosphate phosphohydrolase; EC 3.1.3.9) resulted. (a) At 37 degrees C inhibition was virtually complete and apparently irreversible. (b) At 5 degrees C phospholipase C inhibited 50-87% of the activity expressed by intact control microsomal fractions. (c) Bovine serum albumin present during delipidation alleviated most of this inhibition: at 5 degrees C phospholipase C plus bovine serum albumin inhibited by 0-35% (mean 18%):simultaneous stimulation by the destruction of its latency seems to offset glucose 6-phosphatase inhibition, sometimes completely. (d) If latency was first destroyed, phospholipase C plus bovine serum albumin inhibited 30-50% of total glucose 6-phosphatase activity at 5 degrees C. Only this inhibition is likely largely to reflect the lower availability of phospholipids, essential for maximal enzyme activity, as it is virtually completely reversed by added phospholipid dispersions. Co-dispersions of phosphatidylserine plus phosphatidylcholine (1:1, w/w) were especially effective but Triton X-100 was unable effectively to restore activity. 3. Considerable glucose 6-phosphatase activity survived 240min of treatment with phospholipase C at 5 degrees C, but in the absence of substrate or at physiological glucose 6-phosphate concentrations the delipidated enzyme was completely inactivated within 10min at 37 degrees C. However, 80mM-glucose 6-phosphate stabilized it and phospholipid dispersions substantially restored thermal stability. 4. It is concluded that glucose 6-phosphatase is at least partly phospholipid-dependent, and complete dependence is not excluded. For reasons discussed it is impossible yet to be certain which phospholipid class(es) the enzyme requires for activity.

In situ fabrication of PHEMA–BSA core–corona biohybrid particles

2016 ◽  
Vol 4 (25) ◽  
pp. 4430-4438 ◽  
Author(s):  
Jin-Tao Wang ◽  
Yanhang Hong ◽  
Xiaotian Ji ◽  
Mingming Zhang ◽  
Li Liu ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Atom Transfer ◽  
Hydroxyethyl Methacrylate ◽  
In Situ Fabrication ◽  
Radical Polymerizations

Poly(2-hydroxyethyl methacrylate)–bovine serum albumin core–corona particles were prepared using in situ activators generated by electron transfer for atom transfer radical polymerizations of HEMA initiated by a BSA macroinitiator.

scholarly journals Fabrication of a Novel Antifouling Polysulfone Membrane with in Situ Embedment of Mxene Nanosheets

2019 ◽  
Vol 16 (23) ◽  
pp. 4659 ◽  
Author(s):  
Zhen Shen ◽  
Wei Chen ◽  
Hang Xu ◽  
Wen Yang ◽  
Qing Kong ◽  
...  
Keyword(s):  
Contact Angle ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Water Contact Angle ◽  
Bovine Serum ◽  
Composite Membranes ◽  
Recovery Ratio ◽  
Water Contact ◽  
Polysulfone Membrane

Membrane fouling is still a critical issue for the application of ultrafiltration, which has been widely used in water treatment due to its efficiency and simplicity. In order to improve the antifouling property, a new 2D material MXene was used to fabricate composite ultrafiltration membrane with the approach of in situ embedment during the phase inversion process in this study. Scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), water contact angle, bovine serum albumin rejection and porosity measurements were utilized to characterize the prepared membranes. Due to the hydrophilicity of the MXene, the composite membranes obtained higher hydrophilicity, confirmed by the decreased water contact angle. All the modified membranes had a high bovine serum albumin rejection above 90% while that of the pristine polysulfone membrane was 77.48%. The flux recovery ratio and the reversible fouling ratio of the membranes were also improved along with the increasing content of the MXene. Furthermore, the highest flux recovery ratio could also reach 76.1%. These indicated the good antifouling properties of MXene composite membranes. The enhanced water permeability and protein rejection and excellent antifouling properties make MXene a promising material for antifouling membrane modification.

Binding of the triton X series of nonionic surfactants to bovine serum albumin

Biochemistry ◽  
1980 ◽  
Vol 19 (5) ◽  
pp. 912-917 ◽  
Author(s):  
Wayne W. Sukow ◽  
Howard E. Sandberg ◽  
Edwin A. Lewis ◽  
Delbert J. Eatough ◽  
Lee D. Hansen
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Nonionic Surfactants ◽  
Triton X

scholarly journals Effects of weak bases on the degradation of endogenous and exogenous proteins by rat yolk sacs

1980 ◽  
Vol 188 (3) ◽  
pp. 895-903 ◽  
Author(s):  
G Livesey ◽  
K E Williams ◽  
S E Knowles ◽  
F J Ballard
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Normal Values ◽  
Free Medium ◽  
Weak Base ◽  
Weak Bases ◽  
Endogenous Proteins ◽  
Hydrolysis Of

In rat yolk sacs incubated in vitro, the rates of degradation of endogenous [3H]leucine-labelled proteins and of pinocytically ingested 125I-labelled bovine serum albumin were both decreased in the presence of either ammonium, methylammonium or ethylammonium ions (0-20 mM) or much lower concentrations of chloroquine (0-500 microM). These effects were also accompanied by an inhibition of pinocytosis, as measured by the rate of uptake of 125I-labelled polyvinylpyrrolidone, and by a fall in the [ATP]/[ADP] ratio within the tissue. Re-incubation in inhibitor-free medium of yolk sacs previously exposed to a weak base restored pinocytic and proteolytic capacities, except for tissues exposed to chloroquine at concentrations above 0.1 mM (these appeared to be cytotoxic); an attendent rise in [ATP]/[ADP] ratios to near normal values was also observed. Weak bases, at concentrations that fully arrested the breakdown of 125I-labelled albumin, failed to inhibit by more than 45% the degradation of [3H]leucine-labelled endogenous proteins. Since 125I-labelled bovine serum albumin has been shown to be degraded entirely intralysosomally by yolk sacs, this suggests either that the hydrolysis of endogenous proteins is shared between lysosomes and some other site or that, unlike 125I-labelled albumin, some endogenous proteins can be degraded within lysosomes at abnormally high pH.

A fluorescence turn-on probe for human (bovine) serum albumin based on the hydrolysis of a dioxaborine group promoted by proteins

2017 ◽  
Vol 53 (48) ◽  
pp. 6432-6435 ◽  
Author(s):  
Qian Sun ◽  
Weisi Wang ◽  
Zhaoyang Chen ◽  
Yuhua Yao ◽  
Weibing Zhang ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
High Selectivity ◽  
Biologically Relevant ◽  
Turn On ◽  
Fluorescence Turn On ◽  
Hydrolysis Of

A reaction-based florescence probe CBF for serum albumin (SA) was proposed by connecting a dioxaborine unit with environment-sensitive coumarin fluorophore. CBF exhibits high selectivity and sensitivity toward SA over other biologically relevant species and has potential of detecting SA in biosamples.

In situ modification of lipid-loaded MCM-41 channels with bovine serum albumin at a planar lipid bilayer for biosensing

2011 ◽  
Vol 160 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Keiichiro Nozawa ◽  
Azusa Oshima ◽  
Tomohiro Nasu ◽  
Atsushi Shoji ◽  
Ayumi Hirano-Iwata ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Lipid Bilayer ◽  
Bovine Serum ◽  
Planar Lipid Bilayer ◽  
In Situ Modification ◽  
Mcm 41
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