Micrococcus luteus mediated dual mode synthesis of gold nanoparticles: Involvement of extracellular α-amylase and cell wall teichuronic acid

2013 ◽  
Vol 103 ◽  
pp. 517-522 ◽  
Author(s):  
Pichaimani Arunkumar ◽  
Muthukrishnan Thanalakshmi ◽  
Priyadarsini Kumar ◽  
Kumpati Premkumar
2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Lingyi Lynn Deng ◽  
Alice A. Alexander ◽  
Sijin Lei ◽  
John S. Anderson

The cell wall teichuronic acid (TUA) ofMicrococcus luteusis a long-chain polysaccharide composed of disaccharide repeating units[-4-β-D-ManNAcAp-(1→6)α-D-Glcp−1-]n, which is covalently anchored to the peptidoglycan on the inner cell wall and extended to the outer surface of the cell envelope. An enzyme complex responsible for the TUA chain biosynthesis was purified and characterized. The 440 kDa enzyme complex, named teichuronic acid synthetase (TUAS), is an octomer composed of two kinds of glycosyltransferases, Glucosyltransferase, and ManNAcA-transferase, which is capable of catalyzing the transfer of disaccharide glycosyl residues containing both glucose and theN-acetylmannosaminuronic acid residues. TUAS displays hydrophobic properties and is found primarily associated with the cytoplasmic membrane. The purified TUAS contains carotinoids and lipids. TUAS activity is diminished by phospholipase digestion. We propose that TUAS serves as a multitasking polysaccharide assembling station on the bacterial membrane.


RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20769-20780
Author(s):  
Bhuneshwari Sahu ◽  
Ramsingh Kurrey ◽  
Manas Kanti Deb ◽  
Kamlesh Shrivas ◽  
Indrapal Karbhal ◽  
...  

We report a simple and cost-effective paper-based and colorimetric dual-mode detection of As(iii) and Pb(ii) based on glucose-functionalized gold nanoparticles under optimized conditions.


2017 ◽  
Vol 5 (12) ◽  
pp. 2393-2397 ◽  
Author(s):  
Xiaoying Xu ◽  
Lingzhou Zhao ◽  
Xin Li ◽  
Peng Wang ◽  
Jinhua Zhao ◽  
...  

Multifunctional RGD-modified low-generation dendrimer-entrapped gold nanoparticles can be synthesized and used as a probe for targeted tumor SPECT/CT imaging.


Author(s):  
Zahra Salehi ◽  
Azam Fattahi ◽  
Ensieh lotfali ◽  
Abdolhassan Kazemi ◽  
Ali Shakeri-Zadeh ◽  
...  

Purpose: The present study was performed to examine whether caspofungin-coated gold nanoparticles (CAS-AuNPs) may offer the right platform for sensitivity induction in resistant isolates. Methods: For the purpose of the study, a total of 58 archived Candida species were enrolled in the research. The identification of Candida spp. was performed using polymerase chain reaction-restriction fragment length polymorphism and HWP1 gene amplification approaches. The conjugated CAS-AuNPs were synthesized and then characterized using transmission electron microscopy (TEM) and Zetasizer system to determine their morphology, size, and charge. Furthermore, the efficacy of CAS, CAS-AuNPs conjugate, and AuNPs against Candida spp. was assessed based on the Clinical and Laboratory Standards Institute M60. Finally, the interaction of CAS-AuNPs with Candida element was evaluated via scanning electron microscopy (SEM). Results: According to the TEM results, the synthesized CAS-AuNPs had a spherical shape with an average size of 20 nm. The Zeta potential of CAS-AuNPs was -38.2 mV. Statistical analyses showed that CAS-AuNPs could significantly reduce the minimum inhibitory concentration against C. albicans (P=0.0005) and non-albicans Candida (NAC) species (P<0.0001). All isolates had a MIC value of ≥ 4 µg/ml for CAS, except for C. glabrata. The results of SEM analysis confirmed the effects of AuNPs on the membrane and cell wall structure of C. globrata exposed to CAS-AuNPs, facilitating the formation of pores on the cell wall and finally cell death. Conclusion: The findings revealed that CAS-AuNPs conjugates had significant antifungal effects against Candida spp. through the degradation of the membrane and cell wall integrity. Therefore, it can be concluded that the encapsulation of antifungal drugs in combination with NPs not only diminishes side effects but also enhances the effectiveness of the medications.


2018 ◽  
Vol 42 (14) ◽  
pp. 12126-12133 ◽  
Author(s):  
Ning Li ◽  
Weidan Na ◽  
Hua Liu ◽  
Xingguang Su

Visual and fluorescence detection of amifostine based on the inner filter effect of gold nanoparticles on sulfanilic acid functionalized graphene quantum dots.


2017 ◽  
Vol 5 (13) ◽  
pp. 2395-2401 ◽  
Author(s):  
Du Li ◽  
Jia Yang ◽  
Shihui Wen ◽  
Mingwu Shen ◽  
Linfeng Zheng ◽  
...  

Multifunctional PEI-entrapped gold nanoparticles modified with lactobionic acid enable efficient targeted dual mode CT/MR imaging of human hepatocellular carcinoma.


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