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Bacterioferritin comigratory protein family 1 Cys peroxiredoxin from Candidatus Liberibacter asiaticus (CLaBCP) is an important antioxidant defense protein that participates in the reduction of ROS, free radicals, and peroxides. In the present study, we report the biochemical studies and in silico screening of potent antibacterial molecules against CLaBCP. The CLaBCP showed enzymatic activity with the Km value 54.43, 94.34, 120.6 µM, and Vmax of 59.37, 69.37, 70.0 µM min−1 for H2O2, TBHP, CHP respectively. The residual peroxidase activity of CLaBCP was analyzed at different ranges of pH and temperatures. The CLaBCP showed structural changes and unfolding in the presence of its substrates and guanidinium chloride by CD and fluorescence. The structure-based drug design method was employed to screen and identify the more efficient molecule against CLaBCP. The validated CLaBCP model was used for the virtual screening of potent antibacterial molecules. The docking was performed at CLaBCP active site to evaluate the binding energy of the top five molecules (LAS 34150849, BDE 33184869, LAS 51497689, BDE 33672484, and LAS 34150966). All identified molecule has a higher binding affinity than adenanthin analyzed by molecular docking. Molecular dynamics studies such as RMSD, Rg, SASA, and PCA results showed that the CLaBCP inhibitor(s) complex is more stable than the CLaBCP-adenanthin complex. MMPBSA results suggested that the identified molecule could form a lower energy CLaBCP-inhibiter(s) complex than the CLaBCP-adenanthin complex. The screened molecules may pave the route for the development of potent antibacterial molecules against CLa. Communicated by Ramaswamy H. Sarma

In present work, the recombinant cytoplasmic 2-Cys peroxiredoxin from Citrus sinensis (CsPrx) was purified and characterized. The peroxidase activity was examined with different substrates using DTT, a non-physiological electron donor. The conformational studies, in oxidized and reduced states, were performed using circular dichroism (CD) and fluorescence measurement. The CD analysis showed higher α-helical content for reduced state of the protein. The thermal stability studies of CsPrx by Differential Scanning Calorimetry (DSC) showed that oxidized state is more stable as compared to the reduced state of CsPrx. In vitro studies showed that the CsPrx provides a protective shield against ROS and free radicals that participate in the degradation of plasmid DNA. The pre-treatment of 10 μM CsPrx provide almost 100% protection against peroxide-mediated cell killing in the Vero cells. CsPrx showed significant cell proliferation and wound healing properties. The superior morphology of viable cells and wound closure was found at 20 μM CsPrx treated for 12 h. The results demonstrated that CsPrx is a multifaceted protein with a significant role in cell proliferation, wound healing and protection against hydrogen peroxide-induced cellular damage. This could be the first report of a plant peroxiredoxin being characterized for biomedical applications.

IoT devices are having many constraints related to computation power and memory etc. Many existing cryptographic algorithms of security could not work with IoT devices because of these constraints. Since the sensors are used in large amount to collect the relevant data in an IoT environment, and different sensor devices transmit these data as useful information, the first thing needs to be secure is the identity of devices. The second most important thing is the reliable information transmission between a sensor node and a sink node. While designing the cryptographic method in the IoT environment, programmers need to keep in mind the power limitation of the constraint devices. Mutual authentication between devices and encryption-decryption of messages need some sort of secure key. In the proposed cryptographic environment, there will be a hierarchical clustering, and devices will get registered by the authentication center at the time they enter the cluster. The devices will get mutually authenticated before initiating any conversation and will have to follow the public key protocol.

Huanglongbing is the most destructive disease of citrus worldwide caused by Candidatus Liberibacter asiaticus (CLas). Present control and management could not remove the huanglongbing disease. ZnuA...

The native pumpkin 2S albumin, a multifunctional protein, possess a variety of potential biotechnologically exploitable properties. The present study reports the characterization of recombinant pumpkin 2S albumin (rP2SA) and unraveling of its potential DNA/RNA binding site. The purification and characterization of the rP2SA established that it retains the characteristic α-helical structure and exhibited comparable DNase, RNase, antifungal and anti-proliferative activities as native protein. In vitro studies revealed that rP2SA exhibits potent antiviral activity against chikungunya virus (CHIKV) at a non-toxic concentration with an IC50 of 114.5 μg/mL. In silico studies and site-directed mutagenesis were employed to unravel the potential DNA/RNA binding site. A strong positive charge distribution due to presence of many arginine residues in proximity of helix 5 was identified as a potential site. The two of the arginine residues, conserved in some 2S albumins, were selected for the mutation studies. The mutated forms of recombinant protein (R84A and R91A) showed a drastic reduction in DNase and RNase activities suggesting their presence at binding site and involvement in the nuclease activity. A metal binding site was also identified adjacent to DNA/RNA binding site. The present study demonstrated the structural and functional integrity of the rP2SA and reports potential antiviral activity against CHIKV. Further, potential DNA/RNA binding site was unraveled through mutation studies and bioinformatics analysis.

Hash constructions are used in cryptographic algorithms from very long. Features of Hashes that gives the applications the confidence to use them in security methodologies is “forward secrecy” Forward secrecy comes from one-way hash functions. Examples of earlier hash designs include SHA-3, MD-5, SHA-I, and MAME. Each of these is having their proven record to produce the security for the communication between unconstrained devices. However, this is the era of Internet of Things (IoT) and the requirement of lightweight hash designs are the need of hour. IoT mainly consists of constrained devices. The devices in IoT are having many constrained related to battery power, storage and transmission range. Enabling any security feature in the constrained devices is troublesome. Constrained devices under an IoT environment can work only with less complex and lightweight algorithms. Lightweight algorithms take less power to operate and save a lot of energy of the battery operated devices. SPONGENT, QUARK, HASH-ONE, PHOTON, are some of the well-known lightweight hash designs currently providing security to the IoT devices. In this paper, the authors will present an analysis of the functioning of different lightweight hash designs as well as their suitability to the IoT environment.

Huanglongbing (HLB) is a worldwide citrus plant disease-related to non-culturable and fastidious α-proteobacteria

Huanglongbing (HLB) is a worldwide citrus plant disease-related to non-culturable and fastidious α-proteobacteria Candidatus Liberibacter asiaticus (CLas). In CLas, Peroxiredoxin (Prx) plays a major role in the reduction of the level of reactive species such as reactive oxygen species (ROS), free radicals and peroxides, etc. Here, we have used structure-based drug designing approach was used to screen and identify the potent molecules against 2Cys Prx. The virtual screening of fragments library was performed against the three-dimensional validated model of Prx. To evaluate the binding affinity, the top four molecules (N-Boc-2-amino isobutyric acid (B2AI), BOC-L-Valine (BLV), 1-(boc-amino) cyclobutane carboxylic acid (1BAC), and N-Benzoyl-DL-alanine (BDLA)) were docked at the active site of Prx. The molecular docking results revealed that all the identified molecules had a higher binding affinity than Tert butyl hydroperoxide (TBHP), a substrate of Prx. Molecular dynamics analysis such as RMSD, Rg, SASA, hydrogen bonds, and PCA results indicated that Prx-inhibitor(s) complexes had lesser fluctuations and were more stable and compact than Prx-TBHP complex. MMPBSA results confirmed that the identified compounds could bind at the active site of Prx to form a lower energy Prx-inhibitor(s) complex than Prx-TBHP complex. The identified potent molecules may pave the path for the development of antimicrobial agents against CLA. Communicated by Ramaswamy H. Sarma

The researchers found random numbers beneficial to implement a secure IoT environment. To secure the communications between constrained devices, researchers can use either true random number generators (TRNGs) or pseudorandom number generators (PRNGs) to generate the secure key. Encryption or decryption of the plain text and the mutual authentication between devices uses these keys. PRNGs are highly dependable on TRNGs for the perfect randomness because the randomness of the natural sources or TRNGs is not traceable. Although TRNGs are much safe to generate random numbers, programmers write codes for pseudorandom number generation, commonly known as PRNGs. These PRNGs should use less complicated methods for use in the IoT environment. Authors are writing the programs to generate random numbers independently, without any hardware interruption. In this paper, authors are going to use these concepts to form a new lightweight mechanism for the generation of cryptographically secure random binary bit sequences. Here authors are trying to incorporate the goodness of every flavor at one platform.

A secure environment is needed to communicate without any information leakage. From large devices having UPS to small devices having a battery, the parameter about security changes over time. Researchers need to work in three basics of security: (1) Mutual authentication between devices, (2) Strong encryption methodology for transmission, and (3) Secure storage environment with anytime availability. The IoT-enabled devices demand a lightweight secure environment. In this chapter, authors are concerning on all three points, i.e. Mutual authentication between devices, Strong encryption methodology for transmission, and Secure storage environment with anytime availability. Authors study some of the methods related to lightweight mutual authentication, lightweight cryptography, and local storage techniques; will talk about different issues in the field of secure communication, secure transmission, and secure storage; and will try to find out some research gap with a possible countermeasure.