Heterologous expression of the antimyotoxic protein DM64 in Pichia pastoris

A Systematic Review of the Potential of Pichia pastoris (Komagataella phaffii) as an Alternative Host for Biologics Production

The methylotrophic yeast Pichia pastoris is garnering interest as a chassis cell factory for the manufacture of recombinant proteins because it effectively satisfies the requirements of both laboratory and industrial set up. The optimisation of P. pastoris cultivation is still necessary due to strain- and product-specific problems such as promoter strength, methanol utilisation type, and culturing conditions to realize the high yields of heterologous protein(s) of interest. Techniques integrating genetic and process engineering have been used to overcome these problems. Insight into the Pichia as an expression system utilizing MUT pathway and the development of methanol free systems are highlighted in this systematic review. Recent developments in the improved production of proteins in P. pastoris by (i) diverse genetic engineering such as codon optimization and gene dosage; (ii) cultivating tactics including co-expression of chaperones; (iii) advances in the use of the 2A peptide system, and (iv) CRISPR/Cas technologies are widely discussed. We believe that by combining these strategies, P. pastoris will become a formidable platform for the production of high value therapeutic proteins.

l-Asparaginase Type II from Fusarium proliferatum: Heterologous Expression and In Silico Analysis

The search for new drug-producing microorganisms is one of the most promising situations in current world scientific scenarios. The use of molecular biology as well as the cloning of protein and compound genes is already well established as the gold standard method of increasing productivity. Aiming at this increase in productivity, this work aims at the cloning, purification and in silico analysis of l-asparaginase from Fusarium proliferatum in Komagataella phaffii (Pichia pastoris) protein expression systems. The l-asparaginase gene (NCBI OQ439985) has been cloned into Pichia pastoris strains. Enzyme production was analyzed via the quantification of aspartic B-hydroxamate, followed by purification on a DEAE FF ion exchange column. The in silico analysis was proposed based on the combined use of various technological tools. The enzymatic activity found intracellularly was 2.84 IU/g. A purification factor of 1.18 was observed. The in silico analysis revealed the position of five important amino acid residues for enzymatic activity, and likewise, it was possible to predict a monomeric structure with a C-score of 1.59. The production of the enzyme l-asparaginase from F. proliferatum in P. pastoris was demonstrated in this work, being of great importance for the analysis of new methodologies in search of the production of important drugs in therapy.

Lys49 myotoxins, secreted phospholipase A2-like proteins of viperid venoms: A comprehensive review

Muscle necrosis is a potential clinical complication of snakebite envenomings, which in severe cases can lead to functional or physical sequelae such as disability or amputation. Snake venom proteins with the ability to directly damage skeletal muscle fibers are collectively referred to as myotoxins, and include three main types: cytolysins of the "three-finger toxin" protein family expressed in many elapid venoms, the so-called "small" myotoxins found in a number of rattlesnake venoms, and the widespread secreted phospholipase A₂ (sPLA₂) molecules. Among the latter, protein variants that conserve the sPLA₂ structure, but lack such enzymatic activity, have been increasingly found in the venoms of many viperid species. Intriguingly, these sPLA₂-like proteins are able to induce muscle necrosis by a mechanism independent of phospholipid hydrolysis. They are commonly referred to as "Lys49 myotoxins" since they most often present, among other substitutions, the replacement of the otherwise invariant residue Asp49 of sPLA₂s by Lys. This work comprehensively reviews the historical developments and current knowledge towards deciphering the mechanism of action of Lys49 sPLA₂-like myotoxins, and points out main gaps to be filled for a better understanding of these multifaceted snake venom proteins, to hopefully lead to improved treatments for snakebites.

Current situation of snakebites envenomation in the Neotropics: Biotechnology, a versatile tool in the production of antivenoms

Snakebite envenomation is a neglected tropical disease that affects millions of people around the world with a great impact on health and the economy. Unfortunately, public health programs do not include this kind of disease as a priority in their social programs. Cases of snakebite envenomations in the Neotropics are inaccurate due to inadequate disease management from medical records to the choice of treatments. Victims of snakebite envenomation are primarily found in impoverished agricultural areas where remote conditions limit the availability of antivenom. Antivenom serum is the only Food and Drug Administration-approved treatment used up to date. However, it has several disadvantages in terms of safety and effectiveness. This review provides a comprehensive insight dealing with the current epidemiological status of snakebites in the Neotropics and technologies employed in antivenom production. Also, modern biotechnological tools such as transcriptomic, proteomic, immunogenic, high-density peptide microarray and epitope mapping are highlighted for producing new-generation antivenom sera. These results allow us to propose strategic solutions in the Public Health Sector for managing this disease. Keywords: antivenom, biotechnology, neglected tropical disease, omics, recombinant antibody.

Heterologous expression of recombinant urate oxidase using the intein-mediated protein purification in Pichia pastoris

The potential of urate oxidase (uricase) for clinical use has been highlighted because of its role in lowering the blood uric acid levels for the treatment of tumor lysis syndrome. In the present study, the codon-optimized synthetic gene of Aspergillus flavus uricase was fused to the Mxe GyrA intein and chitin-binding domain. The construct was inserted into pPICZA and pPICZαA vectors and electroporated into Pichia pastoris GS115 for the cytosolic and secretory expression. Transformants were screened on gradients of Zeocin up to 2000 μg/ml to find multi-copy integrants. For both constructs, colonies with more resistance were screened for the highest uricase producers by enzyme assay. PCR analysis confirmed successful cassettes insertion into the genome and Mut + phenotype. The gene copy index was determined to be two and five for cytosolic and secretory strains, respectively. Productivity of the cytosolic and secretory strains was found to be 0.74 and 0.001 U/ml culture media in order while the cytosolic recombinant enzyme accounted for about 6% of total proteins. One-step purification of the expressed uricase was done with the aid of the chitin affinity column, followed by DTT induction for intein on-column cleavage. The yield of 40.8 mg/L and K m of 0.22 mM was obtained for intracellular expression. It seems that the intracellular production of uricase can indeed serve as an effective alternative to secretory expression. Moreover, this is the first report considering cytosolic production of uricase using the intein-mediated protein purification in the methylotrophic yeast, P. pastoris.

Bacterial expression of a snake venom metalloproteinase inhibitory protein from the North American opossum (D.virginiana)

A variety of opossum species are resistant to snake venoms due to the presence of antihemorrhagic and antimyotoxic acidic serum glycoproteins that inhibit several toxic venom components. Two virtually identical antihemorrhagic proteins isolated from either the North American opossum (D. virginiana) or the South American big-eared opossum (D. aurita), termed oprin or DM43 respectively, inhibit specific snake venom metalloproteinases (SVMPs). A better understanding of the structure of these proteins may provide useful insight to determine their mechanism of action and for the development of therapeutics against the global health concern of snake-bite envenomation. The aim of this work is to produce a recombinant snake venom metalloproteinase inhibitor (SVMPI) similar to the above opossum proteins in Escherichia coli and determine if this bacterially produced protein inhibits the proteolytic properties of Western Diamondback rattlesnake (C. atrox) venom. The resulting heterologous SVMPI was produced with either a 6-Histidine or maltose binding protein (MBP) affinity tag on either the C-terminus or N-terminus of the protein, respectively. The presence of the solubility enhancing MBP affinity tag resulted in significantly more soluble protein expression. The inhibitory activity was measured using two complementary assays and the MBP labeled SVMPI showed 7-fold less activity as compared to the 6-Histidine labeled SVMPI. Thus, the bacterially derived SVMPI with an unlabeled N-terminus showed high inhibitory activity (IC₅₀ = 4.5 μM). The use of a solubility enhancing MBP fusion protein construct appears to be a productive way to express sufficient quantities of this mammalian protein in E. coli for further study.

Genome-based engineering of ligninolytic enzymes in fungi

Background

Many fungi grow as saprobic organisms and obtain nutrients from a wide range of dead organic materials. Among saprobes, fungal species that grow on wood or in polluted environments have evolved prolific mechanisms for the production of degrading compounds, such as ligninolytic enzymes. These enzymes include arrays of intense redox-potential oxidoreductase, such as laccase, catalase, and peroxidases. The ability to produce ligninolytic enzymes makes a variety of fungal species suitable for application in many industries, including the production of biofuels and antibiotics, bioremediation, and biomedical application as biosensors. However, fungal ligninolytic enzymes are produced naturally in small quantities that may not meet the industrial or market demands. Over the last decade, combined synthetic biology and computational designs have yielded significant results in enhancing the synthesis of natural compounds in fungi.

Main body of the abstract

In this review, we gave insights into different protein engineering methods, including rational, semi-rational, and directed evolution approaches that have been employed to enhance the production of some important ligninolytic enzymes in fungi. We described the role of metabolic pathway engineering to optimize the synthesis of chemical compounds of interest in various fields. We highlighted synthetic biology novel techniques for biosynthetic gene cluster (BGC) activation in fungo and heterologous reconstruction of BGC in microbial cells. We also discussed in detail some recombinant ligninolytic enzymes that have been successfully enhanced and expressed in different heterologous hosts. Finally, we described recent advance in CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas (CRISPR associated) protein systems as the most promising biotechnology for large-scale production of ligninolytic enzymes.

Short conclusion

Aggregation, expression, and regulation of ligninolytic enzymes in fungi require very complex procedures with many interfering factors. Synthetic and computational biology strategies, as explained in this review, are powerful tools that can be combined to solve these puzzles. These integrated strategies can lead to the production of enzymes with special abilities, such as wide substrate specifications, thermo-stability, tolerance to long time storage, and stability in different substrate conditions, such as pH and nutrients.

Biochemical and functional characterization of a new recombinant phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum

Phospholipase A₂ plays an important role in many diseases. Thus, the production of bioactive molecules, which can modulate PLA₂ activity, became an important target for the pharmaceutical industry. Previously, we demonstrated the inhibitory and anti-angiogenic effect of γCdcPLI, the natural PLA₂inhibitor from Crotalus durissus collilineatus. The aim of the present study was to recombinantly express the γCdcPLI inhibitor and analyze its biochemical and functional characteristics. Based on the amino acid sequence from the natural protein, we designed a synthetic gene for production of a non-tagged recombinant recγCdcPLI using the pHis-Parallel2 vector. To enable disulfide bond formation, protein expression was performed using E. coli Rosetta-gamiB. The protein was purified by anion and affinity chromatography with a yield of 5 mg/L. RecγCdcPLI showed similar secondary structure in CD and FTIR, revealing predominately β-strands. Analogous to the natural protein, recγCdcPLI was able to form oligomers of ~5.5 nm. The inhibitor was efficiently binding to PLA₂ from honeybee (Kd = 1.48 μM) and was able to inhibit the PLA₂ activity. Furthermore, it decreased the vessel formation in HUVEC cells, suggesting an anti-angiogenic potential. Heterologous production of recγCdcPLI is highly efficient and thus enables enhanced drug design for treatment of diseases triggered by PLA₂ activity.

Strategies for recombinant production of antimicrobial peptides with pharmacological potential

INTRODUCTION

The need to develop new drugs for the control of pathogenic microorganisms has redoubled efforts to prospect for antimicrobial peptides (AMPs) from natural sources and to characterize its structure and function. These molecules present a broad spectrum of action against different microorganisms and frequently present promiscuous action, with anticancer and immunomodulatory activities. Furthermore, AMPs can be used as biopharmaceuticals in the treatment of hospital-acquired infections and other serious diseases with relevant social and economic impacts.Areas covered: The low yield and the therefore difficult extraction and purification process in AMPs are problems that limit their industrial application and scientific research. Thus, optimized heterologous expression systems were developed to significantly boost AMP yields, allow high efficiency in purification and structural optimization for the increase of therapeutic activity.Expert opinion: This review provides an update on recent developments in the recombinant production of ribosomal and non-ribosomal synthesis of AMPs and on strategies to increase the expression of genes encoding AMPs at the transcriptional and translational levels and regulation of the post-translational modifications. Moreover, there are detailed reports of AMPs that have already reached marketable status or are in the pipeline under advanced stages of preclinical testing.

Pichia pastoris: A highly successful expression system for optimal synthesis of heterologous proteins

One of the most important branches of genetic engineering is the expression of recombinant proteins using biological expression systems. Nowadays, different expression systems are used for the production of recombinant proteins including bacteria, yeasts, molds, mammals, plants, and insects. Yeast expression systems such as Saccharomyces cerevisiae (S. cerevisiae) and Pichia pastoris (P. pastoris) are more popular. P. pastoris expression system is one of the most popular and standard tools for the production of recombinant protein in molecular biology. Overall, the benefits of protein production by P. pastoris system include appropriate folding (in the endoplasmic reticulum) and secretion (by Kex2 as signal peptidase) of recombinant proteins to the external environment of the cell. Moreover, in the P. pastoris expression system due to its limited production of endogenous secretory proteins, the purification of recombinant protein is easy. It is also considered a unique host for the expression of subunit vaccines which could significantly affect the growing market of medical biotechnology. Although P. pastoris expression systems are impressive and easy to use with well‐defined process protocols, some degree of process optimization is required to achieve maximum production of the target proteins. Methanol and sorbitol concentration, Mut forms, temperature and incubation time have to be adjusted to obtain optimal conditions, which might vary among different strains and externally expressed protein. Eventually, optimal conditions for the production of a recombinant protein in P. pastoris expression system differ according to the target protein.

Yeast Expression Systems: Overview and Recent Advances

Yeasts are outstanding hosts for the production of functional recombinant proteins with industrial or medical applications. Great attention has been emerged on yeast due to the inherent advantages and new developments in this host cell. For the production of each specific product, the most appropriate expression system should be identified and optimized both on the genetic and fermentation levels, considering the features of the host, vector and expression strategies. Currently, several new systems are commercially available; some of them are private and need licensing. The potential for secretory expression of heterologous proteins in yeast proposed this system as a candidate for the production of complex eukaryotic proteins. The common yeast expression hosts used for recombinant proteins' expression include Saccharomyces cerevisiae, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, Arxula adeninivorans, Kluyveromyces lactis, and Schizosaccharomyces pombe. This review is dedicated to discuss on significant characteristics of the most common methylotrophic and non-methylotrophic yeast expression systems with an emphasis on their advantages and new developments.

Purification and characterization of the first γ-phospholipase inhibitor (γPLI) from Bothrops jararaca snake serum

Phospholipases A₂ (PLA₂) are enzymes acting on the cell membrane phospholipids resulting in fatty acids and lysophospholipids and deconstructing the cell membrane. This protein is commonly found in snake venoms, causing tissue inflammation in the affected area. Evidence indicates that snakes have natural resistance to their own venom due to protective properties in plasma, that inhibit the action of proteins present in their venom. Given that, this study aimed to purify and characterize a γPLI from Bothrops jararaca serum, named γBjPLI. PLA₂ inhibitor was isolated using two chromatographic steps: an ion exchange column (DEAE), followed by an affinity column (crotoxin coupled to a CNBr-activated Sepharose resin). The purity and biochemical characterization of the isolated protein were analyzed by RP-HPLC, SEC, SDS-PAGE, circular dichroism and mass spectrometry. The ability to inhibit PLA₂ was determined by enzymatic activity, neutralization of paw edema and myonecrosis. The protein purity was confirmed by RP-HPLC and SEC, whilst an apparent molecular mass of 25 kDa and 20 kDa was obtained by SDS-PAGE, under reducing and non-reducing conditions, respectively. According to mass spectrometry analysis, this protein showed 72% and 68% of coverage when aligned to amino acid sequences of two proteins already described as PLIs. Thus, the inhibitory activity of enzymatic, edema and myonecrotic activities by γBjPLI suggests a role of this inhibitor for protection of these snakes against self-envenomation.