Oligomerization-driven avidity correlates with SARS-CoV-2 cellular binding and inhibition.

Cellular processes are controlled by the thermodynamics of the underlying biomolecular interactions. Frequently, structural investigations use one monomeric binding partner, while ensemble measurements of binding affinities generally yield one affinity representative of a 1:1 interaction, despite the majority of the proteome consisting of oligomeric proteins. For example, viral entry and inhibition in SARS-CoV-2 involve a trimeric spike surface protein, a dimeric angiotensin-converting enzyme 2 (ACE2) cell-surface receptor and dimeric antibodies.

Assessment of Various Nanoprimings for Boosting Pea Germination and Early Growth in Both Optimal and Drought-Stressed Environments.

One of the main climate change-related variables limiting agricultural productivity that ultimately leads to food insecurity appears to be drought. With the use of a recently discovered nanopriming technology, seeds can endure various abiotic challenges. To improve seed quality and initial growth of 8-day-old field pea seedlings (cv.

Phytochemical Composition of Different Red Clover Genotypes Based on Plant Part and Genetic Traits.

Red clover ( L.) is an important legume that is also known as a rich source of isoflavones, which are compounds with mild estrogenic activity. Therefore, this plant is often used as a raw material in the production of dietary supplements recommended in menopause.

A quinolin-8-ol sub-millimolar inhibitor of UGGT, the ER glycoprotein folding quality control checkpoint.

Misfolded glycoprotein recognition and endoplasmic reticulum (ER) retention are mediated by the ER glycoprotein folding quality control (ERQC) checkpoint enzyme, UDP-glucose glycoprotein glucosyltransferase (UGGT). UGGT modulation is a promising strategy for broad-spectrum antivirals, rescue-of-secretion therapy in rare disease caused by responsive mutations in glycoprotein genes, and many cancers, but to date no selective UGGT inhibitors are known. The small molecule 5-[(morpholin-4-yl)methyl]quinolin-8-ol (5M-8OH-Q) binds a UGGT "WY" conserved surface motif conserved across UGGTs but not present in other GT24 family glycosyltransferases.

Rescue of secretion of a rare-disease associated mis-folded mutant glycoprotein in knock-out mammalian cells.

Endoplasmic reticulum (ER) retention of mis-folded glycoproteins is mediated by the ERlocalised eukaryotic glycoprotein secretion checkpoint, UDP-glucose glycoprotein glucosyl-transferase (UGGT). The enzyme recognises a mis-folded glycoprotein and flags it for ER retention by reglucosylating one of its N-linked glycans. In the background of a congenital mutation in a secreted glycoprotein gene, UGGT-mediated ER retention can cause rare disease even if the mutant glycoprotein retains activity ("responsive mutant").

Crystal polymorphism in fragment-based lead discovery of ligands of the catalytic domain of UGGT, the glycoprotein folding quality control checkpoint.

None of the current data processing pipelines for X-ray crystallography fragment-based lead discovery (FBLD) consults all the information available when deciding on the lattice and symmetry (i.e., the polymorph) of each soaked crystal.

Assessing Antigen Structural Integrity through Glycosylation Analysis of the SARS-CoV-2 Viral Spike.

Severe acute respiratory syndrome coronavirus 2 is the causative pathogen of the COVID-19 pandemic which as of March 29, 2021, has claimed 2 776 175 lives worldwide. Vaccine development efforts focus on the viral trimeric spike glycoprotein as the main target of the humoral immune response. Viral spikes carry glycans that facilitate immune evasion by shielding specific protein epitopes from antibody neutralization, and antigen efficacy is influenced by spike glycoprotein production in vivo.

Clamping, bending, and twisting inter-domain motions in the misfold-recognizing portion of UDP-glucose: Glycoprotein glucosyltransferase.

UDP-glucose:glycoprotein glucosyltransferase (UGGT) flags misfolded glycoproteins for ER retention. We report crystal structures of full-length Chaetomium thermophilum UGGT (CtUGGT), two CtUGGT double-cysteine mutants, and its TRXL2 domain truncation (CtUGGT-ΔTRXL2). CtUGGT molecular dynamics (MD) simulations capture extended conformations and reveal clamping, bending, and twisting inter-domain movements.

Networks of HIV-1 Envelope Glycans Maintain Antibody Epitopes in the Face of Glycan Additions and Deletions.

Numerous broadly neutralizing antibodies (bnAbs) have been identified that target the glycans of the HIV-1 envelope spike. Neutralization breadth is notable given that glycan processing can be substantially influenced by the presence or absence of neighboring glycans. Here, using a stabilized recombinant envelope trimer, we investigate the degree to which mutations in the glycan network surrounding an epitope impact the fine glycan processing of antibody targets.

Relationship between incidence of chronic obstructive pulmonary disease and lung cancer as comorbidity in primary health care in two Belgrade communities.

Purpose: To investigate the recent trends in the incidence of chronic obstructive pulmonary disease (COPD) and lung cancer as comorbidity in primary health care (Community Health Center, Zemun, Belgrade, which covers two municipalities - Surchin and Zemun), during the period 2014-2017.

Methods: This retrospective study analyzed the incidence of COPD and lung cancer as comorbidity in a 4-year period. Data were derived from the Heliant information system.

Signature of Antibody Domain Exchange by Native Mass Spectrometry and Collision-Induced Unfolding.

The development of domain-exchanged antibodies offers a route to high-affinity targeting to clustered multivalent epitopes, such as those associated with viral infections and many cancers. One strategy to generate these antibodies is to introduce mutations into target antibodies to drive domain exchange using the only known naturally occurring domain-exchanged anti-HIV (anti-human immunodeficiency virus) IgG1 antibody, 2G12 , as a template. Here, we show that domain exchange can be sensitively monitored by ion-mobility mass spectrometry and gas-phase collision-induced unfolding.

Interdomain conformational flexibility underpins the activity of UGGT, the eukaryotic glycoprotein secretion checkpoint.

Glycoproteins traversing the eukaryotic secretory pathway begin life in the endoplasmic reticulum (ER), where their folding is surveyed by the 170-kDa UDP-glucose:glycoprotein glucosyltransferase (UGGT). The enzyme acts as the single glycoprotein folding quality control checkpoint: it selectively reglucosylates misfolded glycoproteins, promotes their association with ER lectins and associated chaperones, and prevents premature secretion from the ER. UGGT has long resisted structural determination and sequence-based domain boundary prediction.

Potential of Legume-Brassica Intercrops for Forage Production and Green Manure: Encouragements from a Temperate Southeast European Environment.

Legumes and brassicas have much in common: importance in agricultural history, rich biodiversity, numerous forms of use, high adaptability to diverse farming designs, and various non-food applications. Rare available resources demonstrate intercropping legumes and brassicas as beneficial to both, especially for the latter, profiting from better nitrogen nutrition. Our team aimed at designing a scheme of the intercrops of autumn- and spring-sown annual legumes with brassicas for ruminant feeding and green manure, and has carried out a set of field trials in a temperate Southeast European environment and during the past decade, aimed at assessing their potential for yields of forage dry matter and aboveground biomass nitrogen and their economic reliability via land equivalent ratio.

HIV-1 Glycan Density Drives the Persistence of the Mannose Patch within an Infected Individual.

Unlabelled: The HIV envelope glycoprotein (Env) is extensively modified with host-derived N-linked glycans. The high density of glycosylation on the viral spike limits enzymatic processing, resulting in numerous underprocessed oligomannose-type glycans. This extensive glycosylation not only shields conserved regions of the protein from the immune system but also acts as a target for anti-HIV broadly neutralizing antibodies (bnAbs).

The importance of quality control in the implementation of breast cancer screening program in the Health Center Zemun.

Purpose: To investigate whether the differences in implementation between opportunistic and organized breast cancer screening affect the results, as well as the significance of quality control during the implementation of organized breast cancer screening.

Methods: Testing was performed in 2013 (opportunistic screening) and 2014 (organized screening) in the Health Centre Zemun. This included female population aged 50-69 years, belonging to the target population according to the national breast cancer screening programs.

Composition and Antigenic Effects of Individual Glycan Sites of a Trimeric HIV-1 Envelope Glycoprotein.

The HIV-1 envelope glycoprotein trimer is covered by an array of N-linked glycans that shield it from immune surveillance. The high density of glycans on the trimer surface imposes steric constraints limiting the actions of glycan-processing enzymes, so that multiple under-processed structures remain on specific areas. These oligomannose glycans are recognized by broadly neutralizing antibodies (bNAbs) that are not thwarted by the glycan shield but, paradoxically, target it.

Redirecting adenoviruses to tumour cells using therapeutic antibodies: Generation of a versatile human bispecific adaptor.

Effective use of adenovirus-5 (Ad5) in cancer therapy is heavily dependent on the degree to which the virus's natural tropism can be subverted to one that favours tumour cells. This is normally achieved through either engineering of the viral fiber knob or the use of bispecific adaptors that display both adenovirus and tumour antigen receptors. One of the main limitations of these strategies is the need to tailor each engineering event to any given tumour antigen.

Structural Constraints Determine the Glycosylation of HIV-1 Envelope Trimers.

A highly glycosylated, trimeric envelope glycoprotein (Env) mediates HIV-1 cell entry. The high density and heterogeneity of the glycans shield Env from recognition by the immune system, but paradoxically, many potent broadly neutralizing antibodies (bNAbs) recognize epitopes involving this glycan shield. To better understand Env glycosylation and its role in bNAb recognition, we characterized a soluble, cleaved recombinant trimer (BG505 SOSIP.

Glycan Microheterogeneity at the PGT135 Antibody Recognition Site on HIV-1 gp120 Reveals a Molecular Mechanism for Neutralization Resistance.

Broadly neutralizing antibodies have been isolated that bind the glycan shield of the HIV-1 envelope spike. One such antibody, PGT135, contacts the intrinsic mannose patch of gp120 at the Asn332, Asn392, and Asn386 glycosylation sites. Here, site-specific glycosylation analysis of recombinant gp120 revealed glycan microheterogeneity sufficient to explain the existence of a minor population of virions resistant to PGT135 neutralization.