A Comprehensive Review on Euphorbiaceae lectins: Structural and Biological Perspectives

Euphorbiaceae, also known as the spurge family, is a large group of flowering plants. Despite being tropical natives, they are now widespread. Due to its medicinal and commercial importance, this family of plants attracted a lot of attention in the scientific community. The distinctive characteristic of the family is production of milky latex, which is a rich source of several lectins, the proteins that bind carbohydrates. Although their function is unclear, they are believed to defend plants against damaging phytopathogenic microorganisms, insects, and predatory animals. Additionally, they serve as crucial metabolic regulators under a variety of stressors. Detection, separation, purification, and characterization of lectins from the Euphorbiaceae family - mostly from the latex of plants - began over 40 years ago. This effort produced over 35 original research papers that were published. However, no systematic review that compiles these published data has been presented yet. This review summarizes and describes several procedures and protocols employed for extraction and purification of lectins belonging to this family. Physicochemical properties and biological activities of the lectins, along with their medicinal and pharmacological properties, have also been analyzed. Additionally, using examples of ricin and ricin agglutinin, we have structurally analyzed characteristics of the lectin known as Ribosome Inactivating Protein Type II (RIP-Type II) that belongs to this family. We anticipate that this review article will offer a useful compendium of information on this important family of lectins, show the scientists involved in lectin research the gaps in our knowledge, and offer insights for future research.

Association of ABO blood types and clinical variables with COVID-19 infection severity in Libya

Objective

The continuing COVID-19 pandemic is a coronavirus-related health emergency (severe acute respiratory syndrome coronavirus 2). Inadequate efforts are still being made to address the illness situation in Libya, and this must change. To address these issues, we looked into the demography and trend of the disease as well as the potential risk factors for infection.

Methods

This study is a retrospective case-control study conducted online among 616 COVID-19 patients. The p_0.05 value, odds ratios, and 95% confidence intervals were calculated and analyzed from the drawn data.

Results

Males were at high risk of COVID-19 than females (odds ratio = 1.3, 95% confidence interval: 1.042-1.622; p = 0.02). Anosmia and ageusia were more prominent in females. Patients with an "AB" blood group are significantly susceptible to infection. Adults (31 and above) are highly liable to infection. The univariate logistic regression analysis revealed that smoking is a risk factor for those above 60 years (odds ratio = 2.228, 95% confidence interval: 1.145-4.336; p = 0.018). Individuals with chronic diseases such as diabetes and/or hypertension are more prone to COVID-19 (odds ratio = 10.045, 95% confidence interval: 3.078-32.794; p = 0.000 and odds ratio = 11.508, 95% confidence interval: 3.930-33.695; p = 0.000, respectively).

Conclusion

This study provided for the first time the demographic data and the trend of COVID-19 infection in Libya, which will assist the stakeholders and governmental bodies in planning protection strategies against the pandemic.

Phoenix dactylifera (date palm; Arecaceae) putative lectin homologs: Genome-wide search, architecture analysis, and evolutionary relationship

The date palm, Phoenix dactylifera, is a vital crop in nations in the Middle East and North Africa. The date palm was thought to have outstanding traditional medicinal value because it was abundant in phytochemicals with diverse chemical structures. The date palm's ability to withstand harsh environments could be partly attributed to a class of proteins known as lectins, which are carbohydrate-binding proteins that can bind sugar moieties reversibly and without changing their chemical structures. After scanning the genome of P. dactylifera (GCF 009389715.1), this in silico study discovered 196 possible lectin homologs from 11 different families, some specific to plants. At the same time, others could also be found in other kingdoms of life. Their domain architectures and functional amino acid residues were investigated, and they yielded a 40% true-lectin with known conserved carbohydrate-binding residues. Further, their probable subcellular localization, physiochemical and phylogenetic analyses were also performed. Scanning all putative lectin homologs against the anticancer peptide (ACP) dataset found in the AntiCP2.0 webpage identified 26 genes with protein kinase receptors (Lec-KRs) belonging to 5 lectin families, which are reported to have at least one ACP motif. Our study offers the first account of Phoenix-lectins and their organization that can be used for further structural and functional analysis and investigating their potential as anticancer proteins.

Insight into Erythrina Lectins: Properties, Structure and Proposed Physiological Significance

The genus Erythrina, collectively known as “coral tree”, are pantropical plants, comprising of more than 112 species. Since the early 1980s, seven of these have been found to possess hemagglutinating activity, although not yet characterized. However, around two dozen galactose-binding lectins have been isolated and fully characterized with respect to their sugar specificity, glycoconjugates agglutination, dependence of activity on metal ions, primary and secondary structures and stability. Three lectins have been fully sequenced and the crystal structures of the two proteins have been solved with and without the haptenic sugar. Lectins isolation and characterization from most of these species usually originated from the seeds, although the proteins from other vegetative tissues have also been reported. The main objective of this review is to summarize the physicochemical and biological properties of the reported purified Erythrina lectins to date. Structural comparisons, based on available lectins sequences, are also made to relate the intrinsic physical and chemical properties of these proteins. Particular attention is also given to the proposed biological significance of the lectins from the genus Erythrina.

Isolation and partial characterization of 3 nontoxic d-galactose-specific isolectins from seeds of Momordica balsamina

Three isolectins denoted hereforth MBaL-30, MBaL-60, and MBaL-80 were isolated from seeds extract of Momordica balsamina by 30%, 60%, and 80% ammonium sulfate saturations, respectively. The native molecular weights of these lectins, as judged by gel filtration, were 108, 56, and 160 kDa, respectively. On SDS-PAGE, under reduced condition, 27 kDa band was obtained for all isolectins. The lectins hemagglutinating activities were variably inhibited by d-galactose (minimum inhibitory concentrations = 12.5mM, 50mM, and 0.391mM, respectively). MBaL-30 and -60 could agglutinate all human blood types with slight preference for the A and O blood groups, whereas MBaL-80 did not agglutinate B and AB blood types. The 3 isolectins were purified from crude seeds extract, collectively, in a single step on the affinity matrix Lactamyl-Seralose 4B; this purified lectin fraction, which contains all isolectins, is termed MBaL. The N-terminal of MBaL till the 25th amino acid was NLSLSELDFSADTYKSFIKNLRKQL, which shares 88% sequence identity with Momordica charantia lectin type-2 ribosomal inactivating protein from Momordica charantia and 50% with momordin II from Momordica balsamina. MBaL retained 100% activity at up to 50°C for 30 minutes. MBaL-30 and MBaL-60 exhibited maximum activities in the pH range between 4 and 8, while MBaL-80 was showing maximum activity in the pH range between 3 and 5. Treatment of MBaL-30 and MBaL-60 with EDTA completely abolished their hemagglutinating activities. Addition of Zn and Fe ions to the ethylenediaminetetraacetic acid-treated MBaL-30 and MBaL-60 lectins did not only regained the loss of activity but also resulted in 200% to 300% increase in activity, respectively. MBaL-30 and -60 agglutinated gram positive Listeria monocytogenes and Staphylococcus aureus, whereas MBaL-30 could merely agglutinate Escherichia coli. None of these lectins could arrest bacterial growth. Addition of MBaL to cancer cell lines (Gastric cancer cell line (AGS) and Gastric cencer cell line (MKN45), Glioblastoma (ECV-304), and Human urinary bladder cancer cell line (U87-MG)) at varying concentrations did not cause statistically significant changes on cell growth and viability.