Zinc associated nanomaterials and their intervention in emerging respiratory viruses: Journey to the field of biomedicine and biomaterials.

Respiratory viruses represent a severe public health risk worldwide, and the research contribution to tackle the current pandemic caused by the SARS-CoV-2 is one of the main targets among the scientific community. In this regard, experts from different fields have gathered to confront this catastrophic pandemic. This review illustrates how nanotechnology intervention could be valuable in solving this difficult situation, and the state of the art of Zn-based nanostructures are discussed in detail. For virus detection, learning from the experience of other respiratory viruses such as influenza, the potential use of Zn nanomaterials as suitable sensing platforms to recognize the S1 spike protein in SARS-CoV-2 are shown. Furthermore, a discussion about the antiviral mechanisms reported for ZnO nanostructures is included, which can help develop surface disinfectants and protective coatings. At the same time, the properties of Zn-based materials as supplements for reducing viral activity and the recovery of infected patients are illustrated. Within the scope of noble adjuvants to improve the immune response, the ZnO NPs properties as immunomodulators are explained, and potential prototypes of nanoengineered particles with metallic cations (like Zn2+) are suggested. Therefore, using Zn-associated nanomaterials from detection to disinfection, supplementation, and immunomodulation opens a wide area of opportunities to combat these emerging respiratory viruses. Finally, the attractive properties of these nanomaterials can be extrapolated to new clinical challenges.

Advances in molecular engineering of carbohydrate-binding modules.

Carbohydrate-binding modules (CBMs) are non-catalytic domains that are generally appended to carbohydrate-active enzymes. CBMs have a broadly conserved structure that allows recognition of a notable variety of carbohydrates, in both their soluble and insoluble forms, as well as in their alpha and beta conformations and with different types of bonds or substitutions. This versatility suggests a high functional plasticity that is not yet clearly understood, in spite of the important number of studies relating protein structure and function. Several studies have explored the flexibility of these systems by changing or improving their specificity toward substrates of interest. In this review, we examine the molecular strategies used to identify CBMs with novel or improved characteristics. The impact of the spatial arrangement of the functional amino acids of CBMs is discussed in terms of unexpected new functions that are not related to the original biological roles of the enzymes. Proteins 2017; 85:1602-1617. © 2017 Wiley Periodicals, Inc.

The role of conserved non-aromatic residues in the Lactobacillus amylovorus α-amylase CBM26-starch interaction.

It is generally accepted that carbohydrate binding modules (CBMs) recognize their carbohydrate ligands by hydrophobic and CH-π interactions. Point mutations of one CBM26 of the Lactobacillus amylovorus α-amylase starch-binding domain (LaCBM26) showed that conserved non-aromatic residue are essential in the starch recognition function of the domain, as the mutation of a single glutamine (Q68L) eliminates binding to starch and ß-cyclodextrin, even in the presence of aromatic amino acids necessary for ligand binding. The secondary structure of mutated proteins was verified and showed no differences from the wild-type domain. However, random mutations of five residues involved in binding (Y18, Y20, Q68, E74, and F77) did cause change in the secondary structure of the protein, which also causes loss of function. Much of the diversity introduced in the LaCBM26 was probably incompatible with the appropriate folding of these proteins, suggesting that the domain has little tolerance to change.

Data concerning secondary structure and alpha-glucans-binding capacity of the LaCBM26.

Carbohydrate-binding modules (CBMs) are auxiliary domains into glycoside-hydrolases that allow the interaction between the insoluble substrate and the solubilized enzyme, through hydrophobic, CH-π interactions and hydrogen bonds. Here, we present the data article related to the interaction of one LaCBM26 and some mutated proteins with soluble α-glucans determined by enzyme-linked carbohydrate-binding assay, isothermal titration calorimetry (ITC), and affinity gel electrophoresis (AGE). The data of the behavior of proteins in presence and absence of substrate analyzed by circular dichroism CD and thermofluor are also presented. These results are complementary to the research article "The role of conserved non-aromatic residues in the Lactobacillus amylovorus α-amylase CBM26-starch interaction" (Armenta et al., 2019).