scholarly journals Evaluation of Strategies to Produce Highly Porous Cross-Linked Aggregates of Porcine Pancreas Lipase with Magnetic Properties

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2993 ◽  
Author(s):  
José Guimarães ◽  
Raquel Giordano ◽  
Roberto Fernandez-Lafuente ◽  
Paulo Tardioli

The preparation of highly porous magnetic crosslinked aggregates (pm-CLEA) of porcine pancreas lipase (PPL) is reported. Some strategies to improve the volumetric activity of the immobilized biocatalyst were evaluated, such as treatment of PPL with enzyme surface-modifying agents (polyethyleneimine or dodecyl aldehyde), co-aggregation with protein co-feeders (bovine serum albumin and/or soy protein), use of silica magnetic nanoparticles functionalized with amino groups (SMNPs) as separation aid, and starch as pore-making agent. The combination of enzyme surface modification with dodecyl aldehyde, co-aggregation with SMNPs and soy protein, in the presence of 0.8% starch (followed by hydrolysis of the starch with α-amylase), yielded CLEAs expressing high activity (immobilization yield around 100% and recovered activity around 80%), high effectiveness factor (approximately 65% of the equivalent free enzyme activity) and high stability at 40 °C and pH 8.0, i.e., PPL CLEAs co-aggregated with SMNPs/bovine serum albumin or SMNPs/soy protein retained 80% and 50% activity after 10 h incubation, respectively, while free PPL was fully inactivated after 2 h. Besides, highly porous magnetic CLEAs co-aggregated with soy protein and magnetic nanoparticles (pm-SP-CLEAs) showed good performance and reusability in the hydrolysis of tributyrin for five 4h-batches.

1980 ◽  
Vol 188 (3) ◽  
pp. 895-903 ◽  
Author(s):  
G Livesey ◽  
K E Williams ◽  
S E Knowles ◽  
F J Ballard

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.


2017 ◽  
Vol 53 (48) ◽  
pp. 6432-6435 ◽  
Author(s):  
Qian Sun ◽  
Weisi Wang ◽  
Zhaoyang Chen ◽  
Yuhua Yao ◽  
Weibing Zhang ◽  
...  

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.


2017 ◽  
Vol 53 (54) ◽  
pp. 7635-7637 ◽  
Author(s):  
Daily Rodriguez-Padrón ◽  
Alain R. Puente-Santiago ◽  
Alina M. Balu ◽  
Antonio A. Romero ◽  
Rafael Luque

A solventless mechanochemical approach was employed to obtain a bioconjugate (BSA–DA–Fe2O3) based on bovine serum albumin (BSA) and dopamine (DA) coated iron oxide magnetic nanoparticles. BSA molecules retained their native-like structure after the mechanochemical synthesis.


Sign in / Sign up

Export Citation Format

Share Document