Biophysical Investigation of <i>α</i>-Amylase Conjugated Silver Nanoparticles Proves Structural Changes Besides Increasing Its Enzyme Activity

Ernest, Vinita; Nirmala, M. Joyce; Gajalakshmi, S.; Mukherjee, Amitava; Chandrasekaran, N.

doi:10.1166/jbns.2013.1133

Cited by 15 publications

(6 citation statements)

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“…The appearance of a broad absorption band between 1560 cm −1 and 1734 cm −1 with peaks characteristic of both gellan and α-amylase can be observed in the spectrum of sample A4. The absorption peak shift after immobilization represents a change in the structure of the protein from its native form [ 94 ]. The FT-IR spectrum of A4 particles revealed shifts in the absorption peaks characteristic of both gellan and α-amylase.…”

Section: Resultsmentioning

confidence: 99%

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg2+ Ions

et al. 2023

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Amylase is an enzyme used to hydrolyze starch in order to obtain different products that are mainly used in the food industry. The results reported in this article refer to the immobilization of α-amylase in gellan hydrogel particles ionically cross-linked with Mg2+ ions. The obtained hydrogel particles were characterized physicochemically and morphologically. Their enzymatic activity was tested using starch as a substrate in several hydrolytic cycles. The results showed that the properties of the particles are influenced by the degree of cross-linking and the amount of immobilized α-amylase enzyme. The temperature and pH at which the immobilized enzyme activity is maximum were T = 60 °C and pH = 5.6. The enzymatic activity and affinity of the enzyme to the substrate depend on the particle type, and this decreases for particles with a higher cross-linking degree owing to the slow diffusion of the enzyme molecules inside the polymer’s network. By immobilization, α-amylase is protected from environmental factors, and the obtained particles can be quickly recovered from the hydrolysis medium, thus being able to be reused in repeated hydrolytic cycles (at least 11 cycles) without a substantial decrease in enzymatic activity. Moreover, α-amylase immobilized in gellan particles can be reactivated via treatment with a more acidic medium.

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Section: Resultsmentioning

confidence: 99%

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg2+ Ions

et al. 2023

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Section: Bio-functionalized Nanoparticlesmentioning

confidence: 94%

“…A study was done to check the function and structure of starch using hydrolysis. The results were quite interesting in that the structure had no major deformities while still maintaining functionality [5].Since the substrate starch is being fixed onto the surface of silver nanoparticles (AgNPs), the enzyme-substrate complex reaction was proceeding faster than expected. The blue-black colour disappeared 1.5X faster in the presence of AgNPs.…”

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confidence: 97%

Bio-Functionalized Nanoparticles – A Boon for Nano-drug Therapy

Ernest¹,

M²,

Nagarajan³

2017

J Nanomed Nanotechnol

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Bio-functionalization of nanoparticles has received enormous attention due to reduced toxicity as well as stability in colloidal state which prevents the nanoparticles from aggregation [1,2]. The biomolecules being used for functionalization vary from simple to complex macromolecules [3]. Starch, a natural polymer widely used in many industries as raw material was chosen for synthesis of silver nanoparticles as well as for functionalization. The one-pot synthesis was an easy procedure for both synthesis and functionalization [4]. The aldehyde group of starch serves as the functional group which attaches to the synthesized nanoparticles, thereby preventing aggregation. This stabilizes the nanoparticles, and no aggregation was visible for more than three months. A study was done to check the function and structure of starch using hydrolysis. The results were quite interesting in that the structure had no major deformities while still maintaining functionality [5].Since the substrate starch is being fixed onto the surface of silver nanoparticles (AgNPs), the enzyme-substrate complex reaction was proceeding faster than expected. The blue-black colour disappeared 1.5X faster in the presence of AgNPs. The AgNPs were also functionalized with other enzymes to assess structural and functional properties. Lysozyme and amylase from different sources were functionalized over the AgNP, and the corresponding substrates were added and assessed. An increase in the enzymatic activity of enzymes was reported, and lysozyme along with AgNPs was found to have higher bactericidal properties than the free/unbound enzyme [6].In all these studies recorded using various spectroscopic techniques, the structure of enzymes showed few modifications, whereas the function (enzyme activity) was unchanged while being pronounced in the presence of AgNPs [7]. Thus, bio-functionalization not only prevents aggregation but also helps in the immobilization of nanoparticles thereby improving the overall enzyme efficiency [8].In summary, the immobilization of enzymes over the surface of AgNP has yielded a nano-bio-conjugate with synergistic antibacterial and catalytic properties. This strategy opens the door for the development of potential nano-drug delivery systems wherein the biofunctionalized nanoparticles are an immediate option availed in administration of drugs.

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“…According to Carbonaro and Nucara, (2010), the amide I area (C=O stretching vibration) and the amide II region (N-H bending and C-N stretching) were represented by these bands, respectively, hence verified the presence of Mag1 in the samples. These methods were also used by Ernest et al, (2013) and Nawawi et al, (2020) for their observations of amylase samples contained in saliva and Mag1-CLEAs-Tween 20 and Mag1p-CLEAs, respectively. Furthermore, the region of amide I and II can also be used as an indicator for enzymes conformational changes detection (Rabolt et al, 1998;Soleimani, Khani and Najafzadeh, 2012).…”

Section: Chemical Composition Analysismentioning

confidence: 99%

Characterization of Maltogenic Amylase Activity Recovery: A Potential Approach for Improving Immobilization

Jaafar,

Md Illias,

Jailani

et al. 2023

BBT

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Cross-linked enzymes aggregate (CLEA) is a versatile carrier free-immobilization technique that has gained much attention in the development of biocatalyst technology. However, there is no precise and accurate method of using this technique that will lead to an expected outcome that meets the requirements of the industrial standard. Therefore, the objective of this study is to investigate the effect of a few methods of executing cross-linked enzyme aggregates approach using maltogenic amylase by measuring the activity recovery of the developed CLEA. Some factors that are considered in developing the methodologies are the interaction between cross-linkers and enzymes, size of the cross-linked enzyme aggregates and substrate diffusion. The addition of precipitant and the cross-linking agent steps has been manipulated and four different methodologies were developed. Based on the results, Method 2 showed the highest activity recovery (57.9%) whilst Method 4 gave the lowest activity recovery (15.7%). Method 2 is an improvised method that removed supernatant after centrifugation before proceeding to the cross-linking step. The characterization of cross-linked enzyme aggregates such as morphological characterization and Fourier Transform-Infrared Spectroscopy was also determined. In conclusion, the best and most productive preparation method was determined based on the highest activity recovery.

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Biophysical Investigation of α-Amylase Conjugated Silver Nanoparticles Proves Structural Changes Besides Increasing Its Enzyme Activity

Cited by 15 publications

References 1 publication

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg2+ Ions

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg2+ Ions

Bio-Functionalized Nanoparticles – A Boon for Nano-drug Therapy

Characterization of Maltogenic Amylase Activity Recovery: A Potential Approach for Improving Immobilization

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