scholarly journals A comprehensive comparison between camelid nanobodies and single chain variable fragments

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yasaman Asaadi ◽  
Fatemeh Fazlollahi Jouneghani ◽  
Sara Janani ◽  
Fatemeh Rahbarizadeh
Keyword(s):  
Production Cost ◽  
Recombinant Dna ◽  
Antibody Fragments ◽  
Structure And Properties ◽  
Single Chain ◽  
Recombinant Dna Technology ◽  
Variable Domains ◽  
Comprehensive Comparison ◽  
Single Chain Variable Fragments ◽  
Lower Production

AbstractBy the emergence of recombinant DNA technology, many antibody fragments have been developed devoid of undesired properties of natural immunoglobulins. Among them, camelid heavy-chain variable domains (VHHs) and single-chain variable fragments (scFvs) are the most favored ones. While scFv is used widely in various applications, camelid antibodies (VHHs) can serve as an alternative because of their superior chemical and physical properties such as higher solubility, stability, smaller size, and lower production cost. Here, these two counterparts are compared in structure and properties to identify which one is more suitable for each of their various therapeutic, diagnosis, and research applications.

scholarly journals Single Chain Variable Fragment Fused to Maltose Binding Protein: A Modular Nanocarrier Platform for the Targeted Delivery of Antitumorals

2021 ◽  
Author(s):  
Francisco J. Reche-Perez ◽  
Simona Plesselova ◽  
Eduardo De los Reyes-Berbel ◽  
Mariano Ortega-Muñoz ◽  
F. Javier Lopez-Jaramillo ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Targeted Delivery ◽  
Specific Binding ◽  
Protein A ◽  
Antibody Fragments ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Binding Properties ◽  
Single Chain Variable Fragments ◽  
Selective Delivery

The use of the specific binding properties of monoclonal antibody fragments such as single-chain variable fragments (ScFv) for the selective delivery of antitumor therapeutics for cancer cells is attractive due...

scholarly journals Inhibition of Fungal β-1,3-Glucan Synthase and Cell Growth by HM-1 Killer Toxin Single-Chain Anti-Idiotypic Antibodies

2006 ◽  
Vol 50 (9) ◽  
pp. 3090-3097 ◽  
Author(s):  
Dakshnamurthy Selvakumar ◽  
Masahiko Miyamoto ◽  
Yasuhiro Furuichi ◽  
Tadazumi Komiyama
Keyword(s):  
Recombinant Dna ◽  
Killer Toxin ◽  
Binding Assays ◽  
Single Chain ◽  
Recombinant Dna Technology ◽  
Surface Plasmon Resonance Analysis ◽  
Glucan Synthase ◽  
Recombinant Scfv ◽  
Neutralizing Monoclonal Antibody

ABSTRACT Single-chain variable-fragment (scFv) anti-idiotypic antibodies of an HM-1 killer toxin (HM-1) from the yeast Williopsis saturnus var. mrakii IFO 0895 have been produced by recombinant DNA technology from the splenic lymphocytes of mice immunized by idiotypic vaccination with a neutralizing monoclonal antibody (nMAb-KT). The fungicidal activity of scFv anti-idiotypic antibodies against the isolates of four Candida species was assessed by MIC analysis. scFv antibodies were fungicidal at concentrations of 1.56 to 12.5 μg/ml in vitro against four Candida species. The scFv antibodies exerted a strong candidacidal activity in vitro, with 50% inhibitory concentration (IC50) values ranging from 7.3 × 10−8 to 16.0 × 10−8 M, and were neutralized by adsorption with nMAb-KT. Furthermore, all scFv antibodies effectively inhibited fungal β-1,3-glucan synthase activity in vitro, with IC50 values ranging from 2.0 × 10−8 to 22.7 × 10−8 M, values which almost coincide with the values that are inhibitory to the growth of fungal cells. Binding assays showed that the scFv antibodies specifically bind to nMAb-KT, and this binding pattern was confirmed by surface plasmon resonance analysis. The binding ability was further demonstrated by the competition observed between scFv antibodies and HM-1 to bind nMAb-KT. To the best of our knowledge, this is the first study to show that an antifungal anti-idiotypic antibody, in the form of recombinant scFv, potentially inhibits β-1,3-glucan synthase activity.

scholarly journals 44 Amino acids in livestock: A historical perspective

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 22-22
Author(s):  
Keith D Haydon ◽  
R Dean Boyd
Keyword(s):  
Amino Acids ◽  
Chemical Synthesis ◽  
Production Cost ◽  
Recombinant Dna ◽  
Cost Effective ◽  
Commercial Application ◽  
Recombinant Dna Technology ◽  
Umami Taste ◽  
Bacterial Mutants ◽  
Poultry Diets

Abstract The advent of commercially viable synthetic amino acids (AA) and least cost formulation (LCF) have fundamentally changed swine and poultry diets over the past 40 years. Amino acids can be produced by chemical synthesis, hydrolysis of intact proteins and fermentation. Chemical synthesis of AA was first reported by Strecker (1850). Discovery of glutamate as the basis of Umami taste category (1907) spurred commercial AA production by hydrolysis. The discovery of commercially viable fermentative production of glutamate, by Kyowa Hakko Kogyo Co. (1957), revolutionized AA production. Their parallel discovery of lysine (Lys) production, using a natural C. glutmanicum mutant subsequently followed. This led to further screening for bacterial mutants for threonine (Thr, 1961), tryptophan (Trp, 1972), valine (Val, 1959) and isoleucine (Ile, 1972). The next milestone occurred with development of the first main-frame LCF programs (1960s). The first commercial application of dietary AA involved methionine (Met) for poultry, followed closely by Lys in swine. Use of other synthetic AA was cost-prohibitive, but they served as research tools. The next revolution involved recombinant DNA technology (1980s), which dramatically increased AA yield and reduced production cost. Simultaneously, development of PC based LCF enabled cost effective formulation. Subsequently, growth-derived AA ratio’s emerged from the labs of Fuller (1989) and Baker (1992). Patent expirations in the late 1980s led to new companies that produced rapid advances in fermentation methods, with new recombinant strains. Production cost declined further for Lys (1988), and production efficiencies allowed Thr (1995) and Trp (2000) to enter commercial diets. Advances in fermentation technology have enabled production of all ten essential AA. Extensive AA displacement of protein supplements has led to an ever-expanding global tonnage of AA for food and pet animals. With routine addition of 4–6 AA in swine diets, we question whether non-essential AA nitrogen may emerge as limiting (essential).

scholarly journals Antibody Fragments as Tools for Elucidating Structure-Toxicity Relationships and for Diagnostic/Therapeutic Targeting of Neurotoxic Amyloid Oligomers

2020 ◽  
Vol 21 (23) ◽  
pp. 8920
Author(s):  
André L. B. Bitencourt ◽  
Raquel M. Campos ◽  
Erika N. Cline ◽  
William L. Klein ◽  
Adriano Sebollela
Keyword(s):  
Structural Complexity ◽  
Antibody Fragments ◽  
Single Chain ◽  
Amyloidogenic Proteins ◽  
Amyloid Oligomers ◽  
The Central Nervous System ◽  
Single Domain Antibodies ◽  
Single Chain Variable Fragments ◽  
Fragment Antigen Binding

The accumulation of amyloid protein aggregates in tissues is the basis for the onset of diseases known as amyloidoses. Intriguingly, many amyloidoses impact the central nervous system (CNS) and usually are devastating diseases. It is increasingly apparent that neurotoxic soluble oligomers formed by amyloidogenic proteins are the primary molecular drivers of these diseases, making them lucrative diagnostic and therapeutic targets. One promising diagnostic/therapeutic strategy has been the development of antibody fragments against amyloid oligomers. Antibody fragments, such as fragment antigen-binding (Fab), scFv (single chain variable fragments), and VHH (heavy chain variable domain or single-domain antibodies) are an alternative to full-length IgGs as diagnostics and therapeutics for a variety of diseases, mainly because of their increased tissue penetration (lower MW compared to IgG), decreased inflammatory potential (lack of Fc domain), and facile production (low structural complexity). Furthermore, through the use of in vitro-based ligand selection, it has been possible to identify antibody fragments presenting marked conformational selectivity. In this review, we summarize significant reports on antibody fragments selective for oligomers associated with prevalent CNS amyloidoses. We discuss promising results obtained using antibody fragments as both diagnostic and therapeutic agents against these diseases. In addition, the use of antibody fragments, particularly scFv and VHH, in the isolation of unique oligomeric assemblies is discussed as a strategy to unravel conformational moieties responsible for neurotoxicity. We envision that advances in this field may lead to the development of novel oligomer-selective antibody fragments with superior selectivity and, hopefully, good clinical outcomes.

scholarly journals High-yield expression of periplasmic single-chain variable fragments by solid Escherichia coli cultures

BioTechniques ◽  
2021 ◽  
Author(s):  
Yoshiro Hanyu ◽  
Mieko Kato
Keyword(s):  
Escherichia Coli ◽  
Liquid Culture ◽  
Recombinant Antibody ◽  
Antibody Fragments ◽  
High Yield ◽  
Single Chain ◽  
E Coli ◽  
Recombinant Antibody Fragments ◽  
Single Chain Variable Fragments ◽  
High Yields

High-yield expression of quality antibody fragments is indispensable for research and diagnosis. Most recombinant antibody fragments are expressed in Escherichia coli using liquid cultures; however, their yields and quality are often poor. Here the authors expressed a single-chain variable fragment in E. coli cultivated on the wet surface of a solid support. Compared with a liquid culture, the authors obtained 2.5-times more single-chain variable fragments with membrane-cultivated E. coli. This method has two important advantages: it enables high yields of periplasmic single-chain variable fragments compared with liquid culture and offers simple and rapid expression and extraction.

scholarly journals History and Diagnostic Significance of C-Peptide

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Dietrich Brandenburg
Keyword(s):  
Recombinant Dna ◽  
Protein Biosynthesis ◽  
Active Role ◽  
Insulin Biosynthesis ◽  
Single Chain ◽  
Recombinant Dna Technology ◽  
Diagnostic Significance ◽  
C Peptide ◽  
Chemical Structures ◽  
Individual Entity

Starting with the epoch-making discovery of proinsulin, C-peptide has played an important interdisciplinary role, both as part of the single-chain precursor molecule and as an individual entity. In the pioneering years, fundamental systematic experiments unravelled new biochemical mechanisms and chemical structures. After the first detection of C-peptide in human serum, it quickly became a most useful independent indicator of insulin biosynthesis and secretion, finding application in a rapidly growing number of clinical investigations. A prerequisite was the development of specific immuno assays for proinsulin and C-peptide. Further milestones were: the chemical synthesis of several C-peptides and the accomplishments in the synthesis of proinsulin; the detection of preproinsulin with its bearings on understanding protein biosynthesis; the pioneering role of insulin, proinsulin, C-peptide, and mini-C-peptides in the development of recombinant DNA technology; and the discovery of the enzymes for the endoproteolytic processing of proinsulin into insulin and C-peptide, completing the pathway of biosynthesis. Today, C-peptide continues to serve as a special diagnostic tool in Diabetology and related fields. Thus, its passive role is well established. Evidence for its active role in physiology and pathophysiology is more recent and is subject of the following contributions.

Co-expression of recombinant single chain variable fragment recognizing blood antigen fused with sumo and chaperones in Escherichia coli

2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Dang Thi Ngoc Ha ◽  
Le Thi Thu Hong ◽  
Truong Nam Hai
Keyword(s):  
Recombinant Antibody ◽  
Blood Type ◽  
Soluble Form ◽  
Supernatant Fraction ◽  
Blood Group Antigens ◽  
Single Chain ◽  
E Coli ◽  
Recombinant Scfv ◽  
Single Chain Variable Fragments

Single chain variable fragments (scFv) have widely been used in research, diagnosis and treatment, but the scFv is considered as difficult protein for expression in E. coli. In previous studies, we expressed a construction of recombinant single chain variable fragments again antigen specific for blood type A (antiA-scFv) individually or fused with Trx or SUMO. However, soluble fraction was low abandant and only approximately 40% when fused with Trx, the other cases were expressed in form of inclusion body. Therefore, it was difficult for purification, refolding and activity assesment. In thispaper, we demonstrated a suitable construction for soluble production of antiA-scFv fused with SUMO (SM/antiA-scFv) in presence of chaparones. Under fermentation with 0.1 mM IPTG at 20oC, the SM/antiA-scFv was entirely expressed in soluble form. Importantly, after cleavage from SUMO with SUMOprotease, antiA-scFv was still maintained in the supernatant fraction. Therefore, it can help ensure bioactivity and is useful for purification process. To the best of our knowledge, this is the first report showing soluble recombinant scFv fused with SUMO in presence of chaperone for determination of blood group antigens. Thus, this result facilitates the optimal study of soluble expression, purification and bioactivity determination of the antiA-scFv recombinant antibody. 

Enzymatic Synthesis of 15N-L-aspartic Acid Using Recombinant Aspartase from Escherichia Coli K12

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Iulia Lupan ◽  
Sergiu Chira ◽  
Maria Chiriac ◽  
Nicolae Palibroda ◽  
Octavian Popescu
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Enzymatic Synthesis ◽  
Large Scale ◽  
Recombinant Dna ◽  
Industrial Enzymes ◽  
Recombinant Dna Technology ◽  
Bacterial Fermentation ◽  
Natural Protein ◽  
Novel Method

Amino acids are obtained by bacterial fermentation, extraction from natural protein or enzymatic synthesis from specific substrates. With the introduction of recombinant DNA technology, it has become possible to apply more rational approaches to enzymatic synthesis of amino acids. Aspartase (L-aspartate ammonia-lyase) catalyzes the reversible deamination of L-aspartic acid to yield fumaric acid and ammonia. It is one of the most important industrial enzymes used to produce L-aspartic acid on a large scale. Here we described a novel method for [15N] L-aspartic synthesis from fumarate and ammonia (15NH4Cl) using a recombinant aspartase.

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