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ACS Chemical Biology Jun 2024Chemokines are an important family of small proteins integral to leukocyte recruitment during inflammation. Dysregulation of the chemokine-chemokine receptor axis is...
Chemokines are an important family of small proteins integral to leukocyte recruitment during inflammation. Dysregulation of the chemokine-chemokine receptor axis is implicated in many diseases, and both chemokines and their cognate receptors have been the targets of therapeutic development. Analysis of the antigen-binding regions of chemokine-binding nanobodies revealed a sequence motif suggestive of tyrosine sulfation. Given the well-established importance of post-translational tyrosine sulfation of receptors for chemokine affinity, it was hypothesized that the sulfation of these nanobodies may contribute to chemokine binding and selectivity. Four nanobodies (16C1, 9F1, 11B1, and 11F2) were expressed using amber codon suppression to incorporate tyrosine sulfation. The sulfated variant of 16C1 demonstrated significantly improved chemokine binding compared to the non-sulfated counterpart, while the other nanobodies displayed equipotent or reduced affinity upon sulfation. The ability of tyrosine sulfation to modulate chemokine binding, both positively and negatively, could be leveraged for chemokine-targeted sulfo-nanobody therapeutics in the future.
PubMed: 38941516
DOI: 10.1021/acschembio.4c00230 -
Journal of the American Chemical Society Jun 2024Gene expression technology has become an indispensable tool for elucidating biological processes and developing biotechnology. Cell-free gene expression (CFE) systems...
Gene expression technology has become an indispensable tool for elucidating biological processes and developing biotechnology. Cell-free gene expression (CFE) systems offer a fundamental platform for gene expression-based technology, in which the reversible and programmable control of transcription can expand its use in synthetic biology and medicine. This study shows that CFE can be controlled via the host-guest interaction of cucurbit[7]uril (CB[7]) with -guest-modified adenosines. These adenosine derivatives were conveniently incorporated into the DNA strand using a post-synthetic approach and formed a selective and stable base pair with complementary thymidine in DNA. Meanwhile, alternate addition of CB[7] and the exchanging guest molecule induced the reversible formation of a duplex structure through the formation and dissociation of a bulky complex on DNA. The kinetics of the reversibility was fine-tuned by changing the size of the modified guest moieties. When incorporated into a specific region of the T7 promoter sequence, the guest-modified adenosines enabled tight and reversible control of in vitro transcription and protein expression in the CFE system. This study marks the first utility of the host-guest interaction for gene expression control in the CFE system, opening new avenues for developing DNA-based technology, particularly for precise gene therapy and DNA nanotechnology.
PubMed: 38941287
DOI: 10.1021/jacs.4c04262 -
ELife Jun 2024Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we...
Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we examine the impact of mutations across the spectrum of viable amino acid sequences on the biophysical phenotypes of the highly expressed and multifunctional nucleocapsid protein. We find variation in the physicochemical parameters of its extended intrinsically disordered regions (IDRs) sufficient to allow local plasticity, but also observe functional constraints that similarly occur in related coronaviruses. In biophysical experiments with several N-protein species carrying mutations associated with major variants, we find that point mutations in the IDRs can have nonlocal impact and modulate thermodynamic stability, secondary structure, protein oligomeric state, particle formation, and liquid-liquid phase separation. In the Omicron variant, distant mutations in different IDRs have compensatory effects in shifting a delicate balance of interactions controlling protein assembly properties, and include the creation of a new protein-protein interaction interface in the N-terminal IDR through the defining P13L mutation. A picture emerges where genetic diversity is accompanied by significant variation in biophysical characteristics of functional N-protein species, in particular in the IDRs.
Topics: SARS-CoV-2; Coronavirus Nucleocapsid Proteins; Mutation; COVID-19; Humans; Intrinsically Disordered Proteins; Phosphoproteins; Nucleocapsid Proteins; Thermodynamics; Protein Stability
PubMed: 38941236
DOI: 10.7554/eLife.94836 -
Methods in Molecular Biology (Clifton,... 2024Wastewater treatment plants (WWTPs) are the main barrier to cope with the increased pressure of municipal and industrial wastewater on natural water resources in terms...
Wastewater treatment plants (WWTPs) are the main barrier to cope with the increased pressure of municipal and industrial wastewater on natural water resources in terms of both polluting load and produced volumes. For this reason, WWTP's efficiency should be the highest; thus, their monitoring becomes critical. In conventional WWTPs, biodegradation of pollutants mainly occurs in the biological reactors, and an increasing interest in a deeper characterization of the biomasses involved in these processes (made of biofilms, granules, and suspended activated sludge) rose up in recent years. In this sense, the meta-omics approaches were recently developed to investigate the entire set of biomolecules of a given class in a microbial community with the same general objective: the identification of the biomolecules through the sequence similarity of high degree in the already available databases. Particularly, metaproteomics concerns the identification of all proteins in a microbial community in a given moment or condition. In this chapter, a protocol for the extraction and separation of proteins from activate sludge sampled at WWTPs is proposed.
Topics: Sewage; Wastewater; Proteomics; Proteins; Waste Disposal, Fluid
PubMed: 38941010
DOI: 10.1007/978-1-0716-3910-8_2 -
Insights Into Imaging Jun 2024We aimed to develop MRI-based radiomic models (RMs) to improve the diagnostic accuracy of radiologists in characterizing intestinal fibrosis in patients with Crohn's...
OBJECTIVES
We aimed to develop MRI-based radiomic models (RMs) to improve the diagnostic accuracy of radiologists in characterizing intestinal fibrosis in patients with Crohn's disease (CD).
METHODS
This retrospective study included patients with refractory CD who underwent MR before surgery from November 2013 to September 2021. Resected bowel segments were histologically classified as none-mild or moderate-severe fibrosis. RMs based on different MR sequence combinations (RM1: T2WI and enhanced-T1WI; RM2: T2WI, enhanced-T1WI, diffusion-weighted imaging [DWI], and apparent diffusion coefficient [ADC]); RM3: T2WI, enhanced-T1WI, DWI, ADC, and magnetization transfer MRI [MTI]), were developed and validated in an independent test cohort. The RMs' diagnostic performance was compared to that of visual interpretation using identical sequences and a clinical model.
RESULTS
The final population included 123 patients (81 men, 42 women; mean age: 30.26 ± 7.98 years; training cohort, n = 93; test cohort, n = 30). The area under the receiver operating characteristic curve (AUC) of RM1, RM2, and RM3 was 0.86 (p = 0.001), 0.88 (p = 0.001), and 0.93 (p = 0.02), respectively. The decision curve analysis confirmed a progressive improvement in the diagnostic performance of three RMs with the addition of more specific sequences. All RMs performance surpassed the visual interpretation based on the same MR sequences (visual model 1, AUC = 0.65, p = 0.56; visual model 2, AUC = 0.63, p = 0.04; visual model 3, AUC = 0.77, p = 0.002), as well as the clinical model composed of C-reactive protein and erythrocyte sedimentation rate (AUC = 0.60, p = 0.13).
CONCLUSIONS
The RMs, utilizing various combinations of conventional, DWI and MTI sequences, significantly enhance radiologists' ability to accurately characterize intestinal fibrosis in patients with CD.
CRITICAL RELEVANCE STATEMENT
The utilization of MRI-based RMs significantly enhances the diagnostic accuracy of radiologists in characterizing intestinal fibrosis.
KEY POINTS
MRI-based RMs can characterize CD intestinal fibrosis using conventional, diffusion, and MTI sequences. The RMs achieved AUCs of 0.86-0.93 for assessing fibrosis grade. MRI-radiomics outperformed visual interpretation for grading CD intestinal fibrosis.
PubMed: 38940988
DOI: 10.1186/s13244-024-01740-6 -
Current Microbiology Jun 2024Three novel bacterial strains, FE4, FE10, and LA51, which are phylogenetically affiliated to the genera Pseudoalteromonas, Vibrio, or Marinobacter, respectively,...
The Description of Pseudoalteromonas apostichopi sp. nov., Vibrio apostichopi sp. nov., and Marinobacter apostichopi sp. nov. from the Fertilized Eggs and Larvae of Apostichopus japonicus.
Three novel bacterial strains, FE4, FE10, and LA51, which are phylogenetically affiliated to the genera Pseudoalteromonas, Vibrio, or Marinobacter, respectively, isolated from fertilized eggs and juveniles of sea cucumber Apostichopus japonicus were characterized by a genome-based taxonomical approach including multilocus sequence analysis (MLSA) combined with classical phenotypic and chemotaxonomic characterizations. A molecular network reconstructed on the basis of nucleotide sequences of four phylogenetic maker protein genes revealed that the strains FE4, FE10, and LA51 were closely related to Pseudoalteromonas shioyasakiensis, Vibrio lentus, and Marinobacter similis, respectively. Average nucleotide identity (ANI) comparisons against phylogenetically related species to FE4, FE10, and LA51 demonstrated that each newly described strain could not be identified as any previously described species within each genus showing < 95% ANI: 91.3% of FE4 against P. shioyasakiensis JCM 18891, 92.6% of FE10 against "V. bathopelagicus" Sal10, and 92.6% of LA51 against M. similis A3d10, in maximum, respectively. Here, we show molecular phylogenetic, genomic, phenotypic, and chemotaxonomic features of the newly described species FE4, FE10, and LA51. We also propose Pseudoalteromonas apostichopi sp. nov. with FE4 (JCM 36173 = LMG 33143) as the type strain, Vibrio apostichopi sp. nov. with FE10 (JCM 36174 = LMG 33144) as the type strain, and Marinobacter apostichopi sp. nov. with LA51 (JCM 36175 = LMG 33145) as the type strain.
Topics: Pseudoalteromonas; Animals; Phylogeny; Vibrio; Stichopus; Marinobacter; Larva; Multilocus Sequence Typing; DNA, Bacterial; Bacterial Typing Techniques; RNA, Ribosomal, 16S; Zygote; Genome, Bacterial; Fatty Acids
PubMed: 38940874
DOI: 10.1007/s00284-024-03751-4 -
Journal of Integrative Plant Biology Jun 2024Tiller angle is a key agricultural trait that establishes plant architecture, which in turn strongly affects grain yield by influencing planting density in rice. The...
Tiller angle is a key agricultural trait that establishes plant architecture, which in turn strongly affects grain yield by influencing planting density in rice. The shoot gravity response plays a crucial role in the regulation of tiller angle in rice, but the underlying molecular mechanism is largely unknown. Here, we report the identification of the BIG TILLER ANGLE2 (BTA2), which regulates tiller angle by controlling the shoot gravity response in rice. Loss-of-function mutation of BTA2 dramatically reduced auxin content and affected auxin distribution in rice shoot base, leading to impaired gravitropism and therefore a big tiller angle. BTA2 interacted with AUXIN RESPONSE FACTOR7 (ARF7) to modulate rice tiller angle through the gravity signaling pathway. The BTA2 protein was highly conserved during evolution. Sequence variation in the BTA2 promoter of indica cultivars harboring a less expressed BTA2 allele caused lower BTA2 expression in shoot base and thus wide tiller angle during rice domestication. Overexpression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions. Our findings thus uncovered the BTA2-ARF7 module that regulates tiller angle by mediating the shoot gravity response. Our work offers a target for genetic manipulation of plant architecture and valuable information for crop improvement by producing the ideal plant type.
PubMed: 38940609
DOI: 10.1111/jipb.13726 -
Analytical Chemistry Jun 2024Low-mass soluble β-amyloid peptide oligomers (LSAβOs) play a crucial role in the pathogenesis of Alzheimer's disease. However, these oligomers exhibit heterogeneity in...
Low-mass soluble β-amyloid peptide oligomers (LSAβOs) play a crucial role in the pathogenesis of Alzheimer's disease. However, these oligomers exhibit heterogeneity in terms of structure, stability, and stoichiometry, and their abundance in biofluids is low, making accurate identification challenging. In this study, we developed a DNA nanocage-assisted method for selective sizing and sensitive quantification of LSAβOs in serum. Using LSAβO less than 10 kDa (LSAβO) and less than 30 kDa (LSAβO) as models, the size-matching rules between DNA nanocages and LSAβOs were investigated, and two appropriate nanocages were selected for the detection of two LSAβOs, respectively. Both nanocages were functionalized by encapsulating oligomer's aptamer and a complementary sequence within their cavities. Once the LSAβO entered the corresponding nanocage cavity, the complementary sequence was released, triggering a hybridization chain reaction on an electrochemical sensing platform. The system achieved size-selective discrimination of LSAβO with a linear range of 10-150 pM and LSAβO with a linear range of 15-150 pM. Real sample testing confirmed the applicability of the method for blood-based diagnosis. The DNA nanocage-assisted electrochemical analysis platform provides an accurate, highly selective, and sensitive approach for oligomer analysis, which is significant for amyloid protein research and related disease diagnosis.
PubMed: 38940533
DOI: 10.1021/acs.analchem.4c01465 -
Biomeditsinskaia Khimiia Jun 2024Renalase (RNLS) is a recently discovered protein that plays an important role in the regulation of blood pressure by acting inside and outside cells. Intracellular RNLS...
Renalase (RNLS) is a recently discovered protein that plays an important role in the regulation of blood pressure by acting inside and outside cells. Intracellular RNLS is a FAD-dependent oxidoreductase that oxidizes isomeric forms of β-NAD(P)H. Extracellular renalase lacking its N-terminal peptide and cofactor FAD exerts various protective effects via non-catalytic mechanisms. Certain experimental evidence exists in the literature that the RP220 peptide (a 20-mer peptide corresponding to the amino acid sequence RNLS 220-239) reproduces a number of non-catalytic effects of this protein, acting on receptor proteins of the plasma membrane. The possibility of interaction of this peptide with intracellular proteins has not been studied. Taking into consideration the known role of RNLS as a possible antihypertensive factor, the aim of this study was to perform proteomic profiling of the kidneys of normotensive and hypertensive rats using RP220 as an affinity ligand. Proteomic (semi-quantitative) identification revealed changes in the relative content of about 200 individual proteins in the kidneys of hypertensive rats bound to the affinity sorbent as compared to the kidneys of normotensive animals. Increased binding of SHR renal proteins to RP220 over the normotensive control was found for proteins involved in the development of cardiovascular pathology. Decreased binding of the kidney proteins from hypertensive animals to RP220 was noted for components of the ubiquitin-proteasome system, ribosomes, and cytoskeleton.
Topics: Animals; Rats; Kidney; Hypertension; Rats, Inbred SHR; Proteomics; Monoamine Oxidase; Male; Ligands; Peptides; Proteome
PubMed: 38940203
DOI: 10.18097/PBMC20247003145 -
Bioinformatics (Oxford, England) Jun 2024In drug discovery, it is crucial to assess the drug-target binding affinity (DTA). Although molecular docking is widely used, computational efficiency limits its...
MOTIVATION
In drug discovery, it is crucial to assess the drug-target binding affinity (DTA). Although molecular docking is widely used, computational efficiency limits its application in large-scale virtual screening. Deep learning-based methods learn virtual scoring functions from labeled datasets and can quickly predict affinity. However, there are three limitations. First, existing methods only consider the atom-bond graph or one-dimensional sequence representations of compounds, ignoring the information about functional groups (pharmacophores) with specific biological activities. Second, relying on limited labeled datasets fails to learn comprehensive embedding representations of compounds and proteins, resulting in poor generalization performance in complex scenarios. Third, existing feature fusion methods cannot adequately capture contextual interaction information.
RESULTS
Therefore, we propose a novel DTA prediction method named HeteroDTA. Specifically, a multi-view compound feature extraction module is constructed to model the atom-bond graph and pharmacophore graph. The residue concat graph and protein sequence are also utilized to model protein structure and function. Moreover, to enhance the generalization capability and reduce the dependence on task-specific labeled data, pre-trained models are utilized to initialize the atomic features of the compounds and the embedding representations of the protein sequence. A context-aware nonlinear feature fusion method is also proposed to learn interaction patterns between compounds and proteins. Experimental results on public benchmark datasets show that HeteroDTA significantly outperforms existing methods. In addition, HeteroDTA shows excellent generalization performance in cold-start experiments and superiority in the representation learning ability of drug-target pairs. Finally, the effectiveness of HeteroDTA is demonstrated in a real-world drug discovery study.
AVAILABILITY AND IMPLEMENTATION
The source code and data are available at https://github.com/daydayupzzl/HeteroDTA.
Topics: Drug Discovery; Molecular Docking Simulation; Proteins; Deep Learning; Pharmacophore
PubMed: 38940179
DOI: 10.1093/bioinformatics/btae240