Template Preparation, Transcription, & Modification

Restriction Enzymes

Capping Enzymes

Vaccinia capping enzyme is a type of RNA capping enzyme that adds a 7-methylguanosine cap (m7G or m7Gppp) to the 5′-end of an mRNA molecule. This creates the Cap0 structure which protects the mRNA from degradation and is important for efficient translation and export of the mRNA from the nucleus to the cytoplasm.

mRNA cap 2′-O-methyltransferase adds a methyl group to the first nucleotide at the 2′-O position of ribose, resulting in the creation of the Cap1 strcuture (m7GpppNm). This 2′-O-methylation plays a role in authorizing foreign RNA as “self RNA” and hence in the non-self discrimination of the innate immune response against the mRNA.

KACTUS provides GMP-Grade Vaccinia Capping Enzyme and mRNA Cap 2′-O-Methyltransferase designed for use in a one-step capping reaction system to generate the Cap1 structure. Our capping enzymes demonstrate greater than 95% capping efficiency.

E. Coli Poly(A) Polymerase Tailing Enzyme

Cyclization Enzymes

Cyclization enzymes are responsible for forming a unique 5′-5′ phosphodiester bond between the first and last nucleotides of the mRNA molecule, creating what is known as a circular mRNA. This circularization process is important for increasing the stability and translational efficiency of the mRNA molecule, as well as protecting it from degradation by cellular exonucleases.

RNase R digests linear RNA.

RNase R leaves circular RNA intact.

KACTUS offers GMP-Grade CRISPR Cas9 enzymes suitable for manufacturing of cell & gene therapeutics.

FDA Drug Master Files #036578

What are VLP-displayed antigens?

Nanoparticles (20-200nm) derived from outer capsid protein of virus

Formed by the automatic assembly of one or more viral capsid proteins

Surface display provides multiple copies of antigen per VLP to enhance immunogenicity

Why use VLP-displayed antigens?

Do not contain viral infectious genomes, making them safe to use in manufacturing operations

Efficiently activate the body’s humoral and cellular immune responses

Natural configuration of transmembrane proteins for discovery of differentiated antibodies

Validation Data

Fig 1. Flurescent Human Claudin 18.2 VLP used to detect the positive rate of anti-Claudin 18.2 CAR 293T cells

Fig 2. Immobilized Human GPRC5D VLP at 5μg/ml (100μl/Well) on the plate. Dose response curve for Anti-GPRC5D Antibody, hFc Tag with the EC50 of 11.8ng/ml determined by ELISA.

Fig 3. Biotinylated  Human Claudin 6 VLP captured on CM5 Chip via Streptavidin can bind Anti-Claudin6 Antibody with an affinity constant of 0.65 nM as determined in SPR assay (Biacore T200)

Fig 4. The Purity of Human SSTR2 VLP is greater than 95% as determined by SEC-HPLC

The coronavirus disease 2019 (COVID-19) pandemic, due to the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a worldwide health crisis. To support COVID-19 research, KACTUS has developed a series of SARS-CoV-2 and SARS antigens including domains of spike (S) proteins and host cell receptor ACE2.

Product Features

Fig. 1 SDS-PAGE of SARS-CoV-2 Spike S1 and bioactivity assay by ELISA.

Fig. 2 Human ACE2 captured on Protein A chip, can bind SARS-COV-2 Spike RBD, His Tag with an affinity constant of 13.8nM as determined in a SPR assay(Biacore T200).

Fig. 3 Human ACE2 captured on Protein A chip, can bind SARS-COV-2 Spike RBD(N501Y), His Tag with an affinity constant of 1.74nM as determined in a SPR assay(Biacore T200).

Highly active CD3 proteins including monomers, homodimers, heterodimers, and biotinylated

Product Features

High Protein Affinity

.

Equal Expression of Subunits

Stability

Featured Products

Validation Data

Fig 1. Immobilized Human CD3E/CD3G, hFc Tag, at 1μg/ml (100μl/well). Dose-response curve for anti-CD3E/CD3G antibody (OKT3, mFc Tag). The EC50s are 20.7, 19.5, 20.0 and 20.7ng/ml respectively, as determined by ELISA

Fig 2. Human  CD3E/CD3D His Tag, captured on CM5 chip via anti-His antibody, binds OKT3 mFc Tag with an affiinty constant of 0.36nM as determined in SPR assay (Biacore T200).

Fig 3. Immobilized Human CD3E/CD3G, hFc Tag, at 1μg/ml (100μl/well). Dose-response curve for anti-CD3E/CD3G antibody (OKT3, mFc Tag) The EC50s are 20.7,21.0 and 20.0ng/mL respectively as determined by ELISA

Fig 4. Human CD3E/CD3G His Tag, captured on C5 Chip via anti-His antibody, can bind OKT M mFc tag with an affinity constant of 0.22nM as determined in SPR assay (Biacore T200)

Fig 5. The purity of Cynomolgus CD3E is greater than 95% as determined by SEC-HPLC

Fig 6. Cynomolgus CD3E/CD3D on Tris-Bis PAGE under reduced conditions. The purity is greater than 95%

Peptide-MHC I Complexes

Catalog & customized Peptide-MHC complexes

→ Fluorophore Labeling (PE, Cy5, FITC, etc.)

→ Biotinylation

→ Single Chain Peptide-MHC Expression

→ Mammalian & E. coli

→ Tetramerization

→ Custom Peptide Sequences

→ Allelles from Multiple Species (human, mouse, cyno)

Figure 1. Crystallographic alignment of TCR-MCH I/II complexes clears out single-chain MHC design concerns.

Immobilized Anti-P53 R175H (HLA-A*02:01) Antibody, hFc Tag at 5μg/ml (100μl/well) on the plate. Dose response curve for Biotinylated Human P53 R175H (HLA-A*02:01) , His Tag with the EC50 of 1.6μg/ml determined by ELISA. See testing image for detail.

Human GP100 (HLA-A*02:01) Tetramer Protein (MHC-HM402T)

The purity of Human GP100 (HLA-A*02:01) Tetramer was greater than 95% as determined by SEC-HPLC

Human NY-ESO-1 (HLA-A*02:01) Tetramer Protein (MHC-HM405T)

Anti-NY-ESO-1 (HLA-A*02:01) Antibody, hFc Tag captured on CM5 Chip via Protein A can bind Human NY-ESO-1 (HLA-A*02:01) Tetramer, His Tag with an affinity constant of 0.09 nM as determined in SPR assay (Biacore T200).

Human KRAS G12V (HLA-A*03:01) Protein (MHC-HM418)

Immobilized Human NY-ESO-1 (HLA-A*02:01) Tetramer, His Tag at 5μg/ml (100μl/Well) on the plate. Dose response curve for Anti-NY-ESO-1 (HLA-A*02:01) Antibody, hFc Tag with the EC50 of 6.0ng/ml determined by ELISA (QC Test).

Figure 2. Multimeric MHC I-VLP. The structure of MHC I-VLP is illustrated, revealing multiple copies of  MHC I molecules displayed on the surface of the VLP (A). The individual MHC I monomer has a diameter of approximately 70 Å (B), whereas the entire MHC I-VLP complex measures approximately 750 Å in diameter in an electron microscopy image (C).

Features

KACTUS has successfully developed a high-quality Laminin 521 product that can be applied to scientific research (research-grade) and preclinical development (preclinical-grade). It can effectively support the normal growth and passage of PSCs, maintain good stemness, and ensure the homogeneous growth of cells with genetic stability. Laminin 521 can be applied to the cultivation of stem cells and other primary cells and the development of related stem cell products.

Figure 1. The main components of globular basement membrane (GBM) [2].

Product Validation

Figure 3. Normal expression of stem cell markers OCT3/4, SOX2, SSEA4, TRA-1-60, etc.

About Laminin 521

Figure 4. Laminin 521 structure [1].

Mammalian-derived HLA-G and their receptors, LILRB/LILRA in various species and tags for first-in-class drug discovery.

HLA-G, like other immune checkpoints, mediates its function by binding to receptors on immune cells.
The known receptors are from the leukocyte Ig-like receptor (LILR) family and include LILRAs (activating) and LILRBs (suppressing).
When HLA-G binds to LILRBs, tumor cells can escape the surveillance of the immune system.

Owing to their role in activation/supression of immune cells, LILR family proteins have shown broad potential for anti-tumor effects.
LILRBs have become hot targets for drug development, especially for discovery of first-in-class drugs.
The HLA-G and ILT-2/4 signaling pathway is a novel target for monoclonal antibody therapy or cell-based immunotherapy.

Featured Products

Validation Data

We invest considerable time and effort performing quality and activity assays during product development to ensure our proteins are both pure and bioactive.

Fig 1. Human LILRB2, hFc Tag captured onCM5 Chip via Protein A can bind Human HLA-G Tetramer with an affinity constant of 4.62 n/M as determined in SPR assay (Biacore T200)

Fig 2. Serial dilutations of Anti-LILRB2 Antibody were added into Human LILRB2, His Tag: Biotinylated HLA-G Complex Tetramer, His Tag binding reactioins. The half maximal inhibitiory concentration (IC50) is 75.3ng/ml.

Fig 3. The purity of Biotinylated Human APOE3 is greater than 95% as determined by SEC-HPLC

Fig 4. Cynomolgus LILRB2, His Tag immobilized on CM5 Chip can bind Cynomolgus HLA-G Complex Tetramer, His Tag with an affinity constant of 852 nM as determined in SPR assay (Biacore T200)

GMP-Grade & GMP-Ready CRISPR Nucleases.

What makes our Cas9 different?

Using our proprietary protein engineering platform, SAMS™, we have successfully developed a highly active Cas9 protein. Our Cas9 has undergone nuclear localization signal (NLS) design. Additionally, through a series of steps such as protein structure analysis, expression system screening, and formulation optimization, our Cas9 has been optimized for purity and editing activity.

High editing efficacy in multiple cell types

Figure 1. Gene knockout efficiency of our CRISPR Cas9 analyzed in nucleofected 293T, Jurkat, and T cells using TIDE analysis. Results show greater than 95% editing efficacy across all three cell types, comparable to leading suppliers.

High In Vitro Cleavage Activity for AsCas12a

KACTUS also offers a highly active CRISPR-Cas12a enzyme. Cas12a is known for its ability to recognize and cut DNA at a specific site different from the prototypical Cas9. Additionally, Cas12a has been shown to have a lower off-target activity than Cas9, making it a promising tool for precision genome editing.

Figure 2. In vitro cleavage assay using AsCas12a. More than 85% of substrates can be cleaved by our Cas12a Enzyme.

High In Vitro Cleavage Activity for AsCas12a

KACTUS also offers a highly active CRISPR-Cas12a enzyme. Cas12a is known for its ability to recognize and cut DNA at a specific site different from the prototypical Cas9. Additionally, Cas12a has been shown to have a lower off-target activity than Cas9, making it a promising tool for precision genome editing.

Figure 2. In vitro cleavage assay using AsCas12a. More than 85% of substrates can be cleaved by our Cas12a Enzyme.

DNA Amplification and Modification Enzymes

Robust isothermal DNA amplification.

TelN Protelomerase

TelN Protelomerase cleaves dsRNA at its recognition site and leaves covalently closed ends. It can be used for DNA vaccine development as well as for non-viral therapy vectors. TelN Protelomerase is isolated from phage N15.

Exonuclease III

Exonuclease III is a highly processive enzyme that hydrolyzes the phosphodiester bonds in DNA in the 3′ to 5′ direction, resulting in stepwise removal of nucleotides. Exonuclease III catalyzes the removal of nucleotides from linear or nicked double stranded DNA. Degradation of Exonuclease III could be initiated from a 3’ blunt end, 3’ recessed end, 3’ overhangs with less than 4 bases and nicked DNA.

AAV9 Titration ELISA Kit

High specificity, sensitivity, and reproducibility

How it works

Empty AAV9 capsids lacking the transgene of interest cause an unwanted immune response without providing the therapeutic benefit of the transgene. Alongside DNA and infectious titers, determination of the capsid titer is crucial for validating the efficacy and safety of your AAV gene therapy. Our titration kit detects full and empty AAV9 capsids.

This kit uses a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) to determine the quantity of AAV9 capsids in the test sample. The AAV monoclonal antibody is pre-coated on a 96-well reaction plate. AAV9 standard or sample is added to the pre-coated plate, which will specifically bind to the reaction plate. The biotinylated detection antibody is then added to bind the AAV9 capsids. Next, the HRP conjugate is added to form an antibody-antigen complex. HRP will then oxidize TMB substrate to produce a color change. The intensity of the color change is proportional to the AAV9 capsid titer in the sample. After reading the absorbance, the AAV9 capsid titer is calculated based on the absorbance values and the known AAV9 titers of the standard.

Standard Curve

Our AAV9 ELISA kit uses an 8-point standard curve of recombinant AAV9 capsids. Monoclonal AAV9 antibodies precoated on the plate bind the AAV9 capsids. Additional biotinylated AAV9 monoclonal antibodies bind as the second label. The antibodies are serotype-specific and bind only intact AAV9 capsids, not partial capsids. The kit offers two versions of the protocol, a standard procedure (6 hours) which provides greater sensitivity, and a rapid procedure (2 hours) for fast turnaround.

GMP-Grade & GMP-Ready CRISPR Nucleases.

What makes our Cas9 different?

Using our proprietary protein engineering platform, SAMS™, we have successfully developed a highly active Cas9 protein. Our Cas9 has undergone nuclear localization signal (NLS) design. Additionally, through a series of steps such as protein structure analysis, expression system screening, and formulation optimization, our Cas9 has been optimized for purity and editing activity.

High editing efficacy in multiple cell types

Figure 1. Gene knockout efficiency of our CRISPR Cas9 analyzed in nucleofected 293T, Jurkat, and T cells using TIDE analysis. Results show greater than 95% editing efficacy across all three cell types, comparable to leading suppliers.

High In Vitro Cleavage Activity for AsCas12a

KACTUS also offers a highly active CRISPR-Cas12a enzyme. Cas12a is known for its ability to recognize and cut DNA at a specific site different from the prototypical Cas9. Additionally, Cas12a has been shown to have a lower off-target activity than Cas9, making it a promising tool for precision genome editing.

Figure 2. In vitro cleavage assay using AsCas12a. More than 85% of substrates can be cleaved by our Cas12a Enzyme.

High In Vitro Cleavage Activity for AsCas12a

KACTUS also offers a highly active CRISPR-Cas12a enzyme. Cas12a is known for its ability to recognize and cut DNA at a specific site different from the prototypical Cas9. Additionally, Cas12a has been shown to have a lower off-target activity than Cas9, making it a promising tool for precision genome editing.

Figure 2. In vitro cleavage assay using AsCas12a. More than 85% of substrates can be cleaved by our Cas12a Enzyme.

GMP-Grade & GMP-Ready

Enzymes for mRNA Production

Template Preparation, Transcription, & Modification

Full Portfolio mRNA Enzymes

KACTUS offers a full selection of mRNA production enzymes. Many of our enzymes are already manufactured according to cGMP guidelines and have been submitted to the FDA Drug Master Files (DMF). Our remaining enzymes are GMP-Ready, meaning that our team will move them to cGMP standards when it suits your needs.

GMP: Currently manufactured according to cGMP guidelines

DMF: Submitted to the FDA Drug Master Files (DMF) for simplified regulatory applications

All of our other mRNA enzymes can be manufactured in our 100,000 sq ft GMP-Grade facility as necessary.

If you don’t see the enzyme you’re looking for here, contact us about our custom enzyme production services

T7 RNA Polymerase

Our GMP-grade T7 RNA polymerase is engineered to provide high mRNA yield and accurate transcription of mRNA from DNA templates. It is designed to minimze dsRNA contaminzation in transcripts and is free of animal-free of antiobiotics and animal-derived products. Our T7 polymerase has been successfully submitted to the FDA Drug Master Files (#037660).

→ High yield

→ Low dsRNA contamination

→ Stability testing & batch-to-batch consistency

Capping Enzymes

Vaccinia capping enzyme is a type of RNA capping enzyme that adds a 7-methylguanosine cap (m7G or m7Gppp) to the 5′-end of an mRNA molecule. This creates the Cap0 structure which protects the mRNA from degradation and is important for efficient translation and export of the mRNA from the nucleus to the cytoplasm.

mRNA cap 2′-O-methyltransferase adds a methyl group to the first nucleotide at the 2′-O position of ribose, resulting in the creation of the Cap1 strcuture (m7GpppNm). This 2′-O-methylation plays a role in authorizing foreign RNA as “self RNA” and hence in the non-self discrimination of the innate immune response against the mRNA.

KACTUS provides GMP-Grade Vaccinia Capping Enzyme and mRNA Cap 2′-O-Methyltransferase designed for use in a one-step capping reaction system to generate the Cap1 structure. Our capping enzymes demonstrate greater than 95% capping efficiency.

E. Coli Poly(A) Polymerase Tailing Enzyme

Poly(A) polymerase plays a crucial role in mRNA polyadenylation. The enzyme catalyzes the addition of adenosine monophosphates (AMPs) to the 3′ end of the mRNA molecule, creating what is known as the poly(A) tail. The poly(A) tail protects RNA from degradation by nucleases, assists in the transport of RNA out of the nucleus, and stimulates translation of the RNA into protein.

Cyclization Enzymes

Cyclization enzymes are responsible for forming a unique 5′-5′ phosphodiester bond between the first and last nucleotides of the mRNA molecule, creating what is known as a circular mRNA. This circularization process is important for increasing the stability and translational efficiency of the mRNA molecule, as well as protecting it from degradation by cellular exonucleases.

RNase R digests linear RNA

RNase R leaves circular RNA intact.