Protein Organization with Manifold Exploration and Spectral Clustering

We present a method to provide a biologically meaningful representation of the space of protein sequences. While billions of protein sequences are available, organizing this vast amount of information into functional categories is daunting, time-consuming and incomplete. We present our unsupervised approach that combines Transformer protein language models, UMAP graphs, and spectral clustering to create meaningful clusters in the protein spaces. To demonstrate the meaningfulness of the clusters, we show that they preserve most of the signal present in a dataset of manually curated enzyme protein families.

BB0259 Encompasses a Peptidoglycan Lytic Enzyme Function for Proper Assembly of Periplasmic Flagella in Borrelia burgdorferi

Assembly of the bacterial flagellar rod, hook, and filament requires penetration through the peptidoglycan (PG) sacculus and outer membrane. In most β- and γ-proteobacteria, the protein FlgJ has two functional domains that enable PG hydrolyzing activity to create pores, facilitating proper assembly of the flagellar rod. However, two distinct proteins performing the same functions as the dual-domain FlgJ are proposed in δ- and ε-proteobacteria as well as spirochetes. The Lyme disease spirochete Borrelia burgdorferi genome possesses a FlgJ and a PG lytic SLT enzyme protein homolog (BB0259). FlgJ in B. burgdorferi is crucial for flagellar hook and filament assembly but not for the proper rod assembly reported in other bacteria. However, BB0259 has never been characterized. Here, we use cryo-electron tomography to visualize periplasmic flagella in different bb0259 mutant strains and provide evidence that the E580 residue of BB0259 is essential for PG-hydrolyzing activity. Without the enzyme activity, the flagellar hook fails to penetrate through the pores in the cell wall to complete assembly of an intact periplasmic flagellum. Given that FlgJ and BB0259 interact with each other, they likely coordinate the penetration through the PG sacculus and assembly of a functional flagellum in B. burgdorferi and other spirochetes. Because of its role, we renamed BB0259 as flagellar-specific lytic transglycosylase or LTaseBb.

TAT for Enzyme/Protein Delivery to Restore or Destroy Cell Activity in Human Diseases

Much effort has been dedicated in the recent decades to find novel protein/enzyme-based therapies for human diseases, the major challenge of such therapies being the intracellular delivery and reaching sub-cellular organelles. One promising approach is the use of cell-penetrating peptides (CPPs) for delivering enzymes/proteins into cells. In this review, we describe the potential therapeutic usages of CPPs (mainly trans-activator of transcription protein, TAT) in enabling the uptake of biologically active proteins/enzymes needed in cases of protein/enzyme deficiency, concentrating on mitochondrial diseases and on the import of enzymes or peptides in order to destroy pathogenic cells, focusing on cancer cells.

Repurposing of Drugs Targeted Against COVID-19 Spike Receptor for Treatment: An In silico Approach

An escalating pandemic by the novel SARS-CoV2 is spreading across the globe at a rate. An urgent need for therapy is needed. Initially, the virus appeared first in Wuhan, China, and later approximately in 187 countries worldwide. Coronaviruses are causative of respiratory as well as neurological diseases in humans. The novel zoonotic disease-causing coronaviruses are single-stranded RNA viruses. The coronavirus's outer structure consists of spike protein made up of glycoproteins, which binds to ACE (Angiotensin Converting Enzyme) protein when infected in humans. In the current study, 37 compounds that are already used in the biological field as anti-viral compounds are observed with bioinformatics tools. The repurposing drugs are docked against the spike receptor by molecular Docking. The ligand structure and the receptor structure are retrieved from Protein Data Bank. Patch dock server is an open freeware available for docking procedures. The results include acceleration and score of matched properties showing the feasibility of working the drug against SARS-nCoV. For the visualization of the final docked product, PyMOL and RasWin software’s are used. The scores of each ligand docked against the receptor show the compatibility working against the COVID-19 disease.

Identification and Comparison of Peptides from Chickpea Protein Hydrolysates Using Either Bromelain or Gastrointestinal Enzymes and Their Relationship with Markers of Type 2 Diabetes and Bitterness

The chickpea (Cicer arietinum L.) is one of the most important pulses worldwide. The objective was to identify, compare and evaluate peptides from chickpea hydrolysates produced by two enzymatic treatments. The antidiabetic potential and bitterness of the peptides and induction of bitter receptors were identified in silico. Proteins were isolated from the Kabuli variety. Peptides were produced from the proteins using a simulated digestive system (pepsin/pancreatin, 1:50 Enzyme/Protein, E/P), and these peptides were compared with those produced via bromelain hydrolysis (1:50 E/P). The protein profiles, sequences and characteristics of the peptides were evaluated. The biochemical inhibition and molecular docking of dipeptidyl peptidase-IV (DPP-IV), α-amylase and α-glucosidase were also studied. The molecular docking identified peptides from enzymatic hydrolysis as inhibitors of DPP-IV. The high hydrophobicity of the peptides indicated the potential for bitterness. There was no correlation between peptide length and DPP-IV binding. Peptides sequenced from the pepsin/pancreatin hydrolysates, PHPATSGGGL and YVDGSGTPLT, had greater affinity for the DPP-IV catalytic site than the peptides from the bromelain hydrolysates. These results are in agreement with their biochemical inhibition, when considering the inhibition of sitagliptin (54.3 µg/mL) as a standard. The bitter receptors hTAS2R38, hTAS2R5, hTAS2R7 and hTAS2R14 were stimulated by most sequences, which could be beneficial in the treatment of type 2 diabetes. Chickpea hydrolysates could be utilized as functional ingredients to be included in the diet for the prevention of diabetes.

Methods for studying genetic modifications

Objects and modern methods of genome editing are considered. The immune system of prokaryote and their protective mechanisms that prevent the purposeful editing of the genome for the benefit of the researcher is characterized. This mechanism in prokaryotes are cluster regulatory interspatial short palindrome repetitions. The number of such repetitions varies from object to object, which ultimately makes it impossible to get the perfect standard model. Three types of such systems that have their own mechanism for generating proteins have now been identified. The proteins, which are now most commonly used to edit the genome and identify areas of proto-special adjacent motifs, are described. Detailed characteristics of the organization of the immune system prokaryote and phases of its activity are given. Three types of short-palin re-recurrence systems have now been identified, and the teams are being identified as cluster regulatory interspatial short palindrome repetitions-Cas9. Each system uses its own mechanism to generate proteins that catalyze the fission of nucleic acids. The type II cluster regulatory interspatial short palindrome repetitions system is most commonly used, better adapted to edit the genome because of its simplicity. It has been established that the cluster regulatory interspatial short palindrome repetitions-Cas9 system can be used for point editing of the genome and in eukaryotes. This is done either through non-homological annexation of the end, or by homologically directed reparation. A promising variant of genetic modeling is the use of the enzyme-endonuclease Cpf1, which is the effector protein of the cluster regulatory interspatial short palindrome repetitions-Cas V type systems. Cpf1 is smaller than the enzyme protein Cas9 and for the system to function only require specers of ribonucleic acid, without additional ribonucleic acid. Unlike Cas9, which cuts both chains of deoxyribonucleic acid in the same place, Cpf1 generates an incision, creating ticky ends that can be used to insert interesting sequences by complementing and ligation. It is likely that the system using the enzyme-endonuclease Cpf1 will be more convenient than the system where the protein is used Cas9, as the range of editing of the controlled genome of ribonucleic acid is expanded to make the necessary edits.

Kramers’ Theory and the Dependence of Enzyme Dynamics on Trehalose-Mediated Viscosity

The disaccharide trehalose is accumulated in the cytoplasm of some organisms in response to harsh environmental conditions. Trehalose biosynthesis and accumulation are important for the survival of such organisms by protecting the structure and function of proteins and membranes. Trehalose affects the dynamics of proteins and water molecules in the bulk and the protein hydration shell. Enzyme catalysis and other processes dependent on protein dynamics are affected by the viscosity generated by trehalose, as described by the Kramers’ theory of rate reactions. Enzyme/protein stabilization by trehalose against thermal inactivation/unfolding is also explained by the viscosity mediated hindering of the thermally generated structural dynamics, as described by Kramers’ theory. The analysis of the relationship of viscosity–protein dynamics, and its effects on enzyme/protein function and other processes (thermal inactivation and unfolding/folding), is the focus of the present work regarding the disaccharide trehalose as the viscosity generating solute. Finally, trehalose is widely used (alone or in combination with other compounds) in the stabilization of enzymes in the laboratory and in biotechnological applications; hence, considering the effect of viscosity on catalysis and stability of enzymes may help to improve the results of trehalose in its diverse uses/applications.