Crystal structure and nucleic acid binding activity of the conserved UPF0235 family protein PF1765 from Pyrococcus furiosus.

The UPF0235 UniProt family proteins are conserved across archaea, bacteria, and eukaryotes; however, they remain functionally uncharacterized. Here, we report the high resolution (1.3 Å) crystal structure of UPF0235 protein (PF1765, UniProt: Q8U052) from Pyrococcus furiosus.

Recombinant expression and purification of Plasmodium heme detoxification protein in E. coli: Challenges and discoveries.

Heme, a toxic by-product of Plasmodium's proteolytic digestion of host hemoglobin, is detoxified by the malaria parasite through its conversion into hemozoin (Hz)-the malaria pigment. This detoxification pathway is a key target for many antimalarial drugs, which aim to induce heme-mediated toxicity to the parasite. The Heme Detoxification Protein (HDP) plays a central role in heme-to-Hz transformation; however, its precise mechanism remains unclear, largely due to the absence of successful recombinant expression in a native, soluble form.

Recombinant production of de novo designed miniprotein using various fusion protein tags.

Numerous designed miniprotein (4-12 kDa) binders have been developed and reported to exhibit high-affinity interactions with disease targets that show great promise as therapeutic and diagnostic candidates. Despite these advances, detailed methodologies for their production have not been thoroughly explored. We chose two de novo miniprotein binders, LCB1 and AHB2, as model proteins to study their production by recombinant technology using various fusion protein tags.

Structural and Functional Investigation of Putative Peptidase from : An Exclusive Endopeptidase among S9C Subfamily.

Peptidases of the prolyl oligopeptidase (S9 MEROPS) family play a pivotal role in various physiological processes. Among the S9 family, the S9C subfamily is remarkably diverse in exhibiting enzymatic activities such as acylaminoacyl peptidase, dipeptidyl peptidase, endopeptidase, and carboxypeptidase activity. Predicting enzymatic activity for putative peptidase of the S9C subfamily remains a significant challenge.

Crystal Structure of Papain-Like Cysteine Protease, Calotropain FI, Purified from the Latex of .

The latex of and elute as two distinct peaks on cation exchange chromatography. One of the peaks is reported to possess multiple papain-like cysteine proteases with different biochemical properties that have been identified with different names. This is mainly due to the absence of a primary sequence for the proteases.

A cell based assay using virus-like particles to screen AM type mimics for SARS-CoV-2 neutralisation.

A number of small molecule and protein therapeutic candidates have been developed in the last four years against SARS-CoV-2 spike. However, there are hardly a few molecules that have advanced through the subsequent discovery steps to eventually work as a therapeutic agent. This is majorly because of the hurdles in determining the affinity of potential therapeutics with live SARS-CoV-2 virus.

Amino acid propensities for secondary structures and its variation across protein structures using exhaustive PDB data.

Amino acid propensities for protein secondary structures are vital for protein structure prediction, understanding folding, and design, and have been studied using various theoretical and experimental methods. Traditional assessments of average propensities using statistical methods have been done on relatively smaller dataset for only a few secondary structures. They also involve averaging out the environmental factors and lack insights into consistency of preferences across diverse protein structures.

Crystal structure of a newly identified M61 family aminopeptidase with broad substrate specificity that is solely responsible for recycling acidic amino acids.

Aminopeptidases with varied substrate specificities are involved in different crucial physiological processes of cellular homeostasis. They also have wide applications in food and pharma industries. Within the bacterial cell, broad specificity aminopeptidases primarily participate in the recycling of amino acids by degrading oligopeptides generated via primary proteolysis mediated by cellular ATP-dependent proteases.

Characterization of a secreted aminopeptidase of M28 family from B. fragilis and its possible role in protein metabolism in the gut.

Products of microbial protein metabolism in the gut can influence the health of the host in many ways. Members of the Bacteriodales, major commensals of the human colon have been associated with long-term intake of high-protein diets. Undigested proteins or peptides that reach the colon can be hydrolyzed by extra-cellular proteases found in some Bacteroides species into amino acids and peptides which can be further catabolized.

Crystal structure and solution scattering of Geobacillus stearothermophilus S9 peptidase reveal structural adaptations for carboxypeptidase activity.

Acylaminoacyl peptidases (AAPs) play a pivotal role in various pathological conditions and are recognized as potential therapeutic targets. AAPs exhibit a wide range of activities, such as acylated amino acid-dependent aminopeptidase, endopeptidase, and less studied carboxypeptidase activity. We have determined the crystal structure of an AAP from Geobacillus stearothermophilus (S9gs) at 2.

Design of human ACE2 mimic miniprotein binders that interact with RBD of SARS-CoV-2 variants of concerns.

The world of medicine demands from the research community solutions to the emerging problem of SARS-CoV-2 variants and other such potential global pandemics. With advantages of specificity over small molecule drugs and designability over antibodies, miniprotein therapeutics offers a unique solution to the threats of rapidly emerging SARS-CoV-2 variants. Unfortunately, most of the promising miniprotein binders are designed and it is not viable to generate molecules for each new variant.

The crystal structure of insecticidal protein Txp40 from Xenorhabdus nematophila reveals a two-domain unique binary toxin with homology to the toxin-antitoxin (TA) system.

Txp40 is a ubiquitous, conserved, and novel toxin from Xenorhabdus and Photorhabdus bacteria, toxic to a wide range of insect pests. However, the three-dimensional structure and toxicity mechanism for Txp40 or any of its sequence homologs are not yet known. Here, we are reporting the crystal structure of the insecticidal protein Txp40 from Xenorhabdus nematophila at 2.

20-kDa accessory protein (P20) from Bacillus thuringiensis subsp. israelensis ISPC-12: Purification, characterization, solution scattering and structural analysis.

The 20-kDa accessory protein (P20) from Bacillus thuringiensis subsp. israelensis (Bti) has been identified as an essential molecular chaperone in the enhancement of Cry11Aa and Cyt1Aa toxins production and their bio-crystallization. Additionally, P20 plays a vital role in suppressing the toxic effect of Cyt toxin on the host bacterium and also enhances insecticidal activity of Cry1Ac protein.

Crystal structures of PirA and PirB toxins from Photorhabdus akhurstii subsp. akhurstii K-1.

PirAB binary toxin from Photorhabdus is toxic to the larvae of dipteran and lepidopteran insect pests. However, the 3-D structures and their toxicity mechanism are not yet fully understood. Here we report the crystal structures of PirA and PirB proteins from Photorhabdus akhurstii subsp.

Investigation Unveiling New Insights into the Antimalarial Mechanism of Chloroquine: Role in Perturbing Nucleation Events during Heme to β-Hematin Transformation.

Malaria parasites generate toxic heme during hemoglobin digestion, which is neutralized by crystallizing into inert hemozoin (β-hematin). Chloroquine blocks this detoxification process, resulting in heme-mediated toxicity in malaria parasites. However, the exact mechanism of chloroquine's action remains unknown.

Crystal structure of phosphate bound Acyl phosphatase mini-enzyme from Deinococcus radiodurans at 1Ã… resolution.

Acylphosphatase (Acp) is a hydrolase which specifically cleaves carboxyl-phosphate bond of intermediates of metabolic pathways. It is a small cytosolic enzyme found in both prokaryotic and eukaryotic organisms. Previous crystal structures of acylphosphatase from different organisms have provided insights into the active site but the complete understanding of substrate binding and catalytic mechanisms in acylphosphatase remain elusive.

Purification, characterization and proteolytic processing of mosquito larvicidal protein Cry11Aa from Bacillus thuringiensis subsp. israelensis ISPC-12.

Cry11Aa is the most potent mosquito larvicidal protein of Bacillus thuringiensis subsp. israelensis (Bti). Development of resistance against insecticidal proteins including Cry11Aa is known but no field resistance was observed with Bti.

Assessing the prospect of XAFS experiments of metalloproteins under in vivo conditions at Indus-2 synchrotron facility, India.

The feasibility of X-ray absorption fine-structure (XAFS) experiments of ultra-dilute metalloproteins under in vivo conditions (T = 300 K, pH = 7) at the BL-9 bending-magnet beamline (Indus-2) is reported, using as an example analogous synthetic Zn (0.1 mM) M1dr solution. The (Zn K-edge) XAFS of M1dr solution was measured with a four-element silicon drift detector.

Purification, characterization and toxicity assessment of PirAB toxins from Photorhabdus akhurstii subsp. akhurstii K-1.

Photorhabdus insect related proteins A & B (PirA, PirB) from Photorhabdus and Xenorhabdus bacteria exhibit both oral and injectable toxicity against lepidopteran and dipteran insect pest. The pirA, pirAt (encoding 6 N-terminal truncated PirA), pirB genes, pirA-pirB (with ERIC sequences), pirA-pirB-mERIC (modified pirA-pirB with mutated ERIC sequences) and polycistronic-pirAB were cloned and expressed in Escherichia coli. However, PirA protein was expressed in insoluble form and therefore the pirA gene was modified to produce PirAt.

Txp40, an insecticidal toxin protein from Xenorhabdus nematophila: Purification, toxicity assessment and biophysical characterization.

Txp40 is a ubiquitous toxin from Xenorhabdus and Photorhabdus bacteria, exhibits insecticidal activity against a wide range of insect pests belonging to Lepidoptera and Diptera orders. Initially, Txp40 affects midgut of the target insect and further damages some other tissues like fat bodies but the detailed mode of action is not known. Txp40 shares no significant sequence match to any proteins with known structure or function, suggesting that it is a novel type of insecticidal toxin.

Dithiophosphonate Anchored Heterometallic (Ag(I)/Fe(II)) Molecular Catalysts for Electrochemical Hydrogen Evolution Reaction.

The dichalcogenide ligated molecules in catalysis to produce molecular hydrogen through electroreduction of water are rarely explored. Here, a series of heterometallic [Ag(SPFc(OR)] [where Fc = Fe(η-CH)(η-CH), R = Me, ; Et, ; Pr, ; Amyl, ] clusters were synthesized and characterized by IR, absorption spectroscopy, NMR (H, P), and electrospray ionization mass spectrometry. The molecular structures of , , and clusters were established by single-crystal X-ray crystallographic analysis.

An assay procedure to investigate the transformation of toxic heme into inert hemozoin via plasmodial heme detoxification protein.

Most antimalarial therapeutics, including chloroquine and artemisinin, induce free heme-mediated toxicity in Plasmodium. This cytotoxic heme is produced as a by-product during the large-scale digestion of host hemoglobin. Conversion of this host-derived heme into inert crystalline hemozoin is the only defense mechanism in Plasmodium against heme-induced cytotoxicity.

Isolation and characterization of a recombinant class C acid phosphatase from sp. RSMS strain.

Tributyl phosphate (TBP) is extensively used in nuclear industry and is a major environmental pollutant. The mechanism for TBP degradation is not identified in any TBP-degrading bacteria. Here, we report identification of an acid phosphatase from sp.

Autoproteolysis of Procerain and Procerain B mediated by structural changes.

Procerain (Pc) and Procerain B (PcB) are two latex proteases from Calotropis procera having potential applications in food and other industries. However, autolytic degradation of these proteases limits their potential use in industry. Nevertheless, basic mechanism underlying the autoproteolysis has not been detailed.