scholarly journals A Turn-On Fluorescent Sensor for Glutathione Based on Bovine Serum Albumin-Stabilized Gold Nanoclusters

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Yan Qiu ◽  
Jianlin Huang ◽  
Li Jia

A fluorescence sensor for the detection of glutathione based on the fluorescence recovering of the bovine serum albumin-stabilized gold nanoclusters is reported. This study indicates that glutathione restores the copper-ion-quenched fluorescence by coordinating the bound copper ion in the bovine serum albumin molecule used for stabilizing the gold nanocluster through its sulfydryl. Under the experimental conditions, the fluorescence response showed a linear relationship with the concentration of glutathione over the range from 10 µM to 400 µM. The fluorescence sensor successfully detected glutathione in commercial drug products.

2012 ◽  
Vol 17 (1) ◽  
pp. 72
Author(s):  
Janeth Arias-Palacios ◽  
Libardo Hernandez-Esquivel ◽  
Juan Carlos Marín-Díaz ◽  
Natalia Navarro-Peña ◽  
Natalia Santos-Arévalo

<strong>Objective</strong>. Evaluate the dilution-neutralization method proposed in the Colombian Technical Norm 5473/07, by using a gel, alcoholbased disinfectant. <strong>Materials and methods</strong>. This study was done using Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538, and Enterococcus hirae ATCC 10541 as the assay microorganisms. The study was carried out at 20±1°C as obligatory temperature and additionally at 36±1°C. Four contact times between microorganisms and the disinfectant were evaluated (0, 2, 5 and 10 minutes). The assay was done both under clean conditions (0.3 g/L of bovine serum albumin), and unclean conditions (3 g/L of bovine serum albumin and 3g/L of sheep erythrocytes). <strong>Results</strong>. The implementation of this method produced precise results in all of the six<br />repetitions used during the assay. The obtained results demonstrated a logarithmic reduction higher than five, demonstrating the bactericidal activity exerted by the disinfectant on the control microorganisms. The established experimental conditions and methodology did not affect negatively the growth of any of the strains of microorganisms. Similarly, the neutralizing used did not inhibit the development of the microorganisms of the assay.<strong> Conclusions</strong>. The method was verified by means of the fulfillment of the limits set by the rule. Our results suggest that the method evaluated by means of the implementation of the protocol established in the Colombian Technical Norm 5473/07, allows evaluating the effectiveness of a disinfectant under selected and controlled experimental conditions.<br /><br /><strong>Key words</strong>: disinfection, clean conditions, unclean conditions, dilution-neutralization method, logarithmic reduction.


2020 ◽  
Vol 153 ◽  
pp. 104453 ◽  
Author(s):  
Munira Khatun ◽  
Gopal Chandra Jana ◽  
Sk Nayim ◽  
Somnath Das ◽  
Anirudha Patra ◽  
...  

1988 ◽  
Vol 250 (2) ◽  
pp. 477-484 ◽  
Author(s):  
R P Hafner ◽  
M D Brand

We investigated reports that mitochondria isolated from hypothyroid rats have decreased ADP/O and H+/O ratios. We observed no decrease in the H+/O ratio in mitochondria from hypothyroid rats, in the presence of either 2% (w/v) fatty-acid-free bovine serum albumin or 100 nM free Ca2+. The ADP/O ratio in mitochondria isolated from hypothyroid rats in the presence of 2% fatty-acid-free bovine serum albumin was measured. Under normal experimental conditions we found no decrease in the ADP/O ratio, relative to that measured for littermate controls. At the low concentrations of mitochondrial protein used in the previously reported studies, the ADP/O ratio of mitochondria from hypothyroid rats was decreased, whereas that for control rats was only slightly decreased. The difference between the ADP/O ratios measured for mitochondria form hypothyroid rats and from control rats under these conditions was eliminated by inhibition of endogenous adenylate kinase. We suggest that the lowering of the apparent ADP/O ratio in mitochondria from hypothyroid rats at low concentrations of mitochondrial protein is an experimental artefact resulting from the breakdown of ADP to AMP.


Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1630 ◽  
Author(s):  
Yu-Chen Hsu ◽  
Mei-Jou Hung ◽  
Yi-An Chen ◽  
Tsu-Fan Wang ◽  
Ying-Ru Ou ◽  
...  

The reducing and capping sites along with their local structure impact photo properties of the red bovine serum albumin-capped Au nanocluster (BSA-AuNC), however, they are hard to identify. We developped a workflow and relevant techniques using mass spectrometry (MS) to identify the reducing and capping sites of BSA-AuNCs involved in their formation and fluorescence. Digestion without disulfide cleavages yielded an Au core fraction exhibiting red fluorescence and [AunSm] ion signals and a non-core fraction exhibiting neither of them. The core fraction was identified to mainly be comprised of peptides containing cysteine residues. The fluorescence and [AunSm] signals were quenched by tris(2-carboxyethyl)phosphine, confirming that disulfide groups were required for nanocluster stabilization and fluorescence. By MS sequencing, the disulfide pairs, C75–C91/C90–C101 in domain IA, C315–C360/C359–C368 in domain IIB, and C513–C558/C557–C566 in domain IIIB, were identified to be main capping sites of red AuNCs. Peptides containing oxidized cysteines (sulfinic or cysteic acid) were identified as reducing sites mainly in the non-core fraction, suggesting that disulfide cleavages by oxidization and conformational changes contributed to the subsequent growth of nanoclusters at nearby intact disulfide pairs. This is the first report on precise identification of the reducing and capping sites of BSA-AuNCs.


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