Avi-tag and chemically labeled biotinylated proteins

NEW Avi-tag Spike and ACE-2 Proteins for SARS-CoV-2 Research. Interested in more proteins for COVID-19 research? Visit our Recombinant Proteins for Coronavirus Research page.

R&D Systems offers a wide assortment of biotinylated proteins allowing researchers to take the guesswork out of protein biotinylation. In addition to amine-labeled biotinylated proteins, we have a growing list of Avi-tag biotinylated proteins. Each biotinylated protein is held to the same industry-leading quality standards as their unlabeled counterpart while also limiting batch-to-batch variability. Also, the R&D Systems Custom Protein Development Team can work with you to create a customized protein solution to meet your specific research needs.

Advantages of Avi-tag Biotinylated
Recombinant Proteins

1. Consistent labeling. Biotinylation only occurs on the single lysine residue in the Avi-tag.
2. Uniform orientation of protein. When bound to a streptavidin-coated surface, the avitagged protein orientation will be uniform due to the precise control over biotinylation.
3. Equivalent bioactivity. Because biotinylation is restricted to the Avi-tag, the rest of the protein is unchanged so there is no interference in the protein’s bioactivity.
4. Lot-to-lot consistency. Each new lot is tested side-by-side with previous lots and with a master lot to ensure high lot-to-lot consistency.

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Avi-tag biotinylated recombinant protein binding to streptavidin-coated surface

Avi-tag Biotinylated Proteins – Products by Molecule

2B4/CD244/SLAMF4	4-1BB/TNFRSF9	5'-Nucleotidase/CD73	5T4	ACE-2	ALCAM/CD166
Axl	B7-1/CD80	B7-2/CD86	B7-H2	B7-H3	B7-H4
B7-H6	BCMA	BTN1A1/Butyrophilin	BTN2A1	BTN3A2	CD3 delta
CD4	CD6	CD8 alpha	CD19	CD24	CD25/IL-2 R
CD27	CD28	CD30/TNFRSF8	CD38	CD40/TNFRSF5	CD44v5
CD47	CD48/SLAMF2	CD117/c-kit	CD155/PVR	CD200	CD200 R1
CEACAM-1/CD66a	CEACAM-5/CD66e	CEACAM-6/CD66c	Common gamma chain	CTLA-4	CX3CL1/Fractalkine
CRACC/SLAMF7	DLL4	DNAM-1/CD226	DPPIV/CD26	EGFR	EpCAM/TROP1
ErbB2/Her2	ErbB3/Her3	Fc epsilon RI alpha	Fc gamma RIIB/CD32b	Fc gamma RIIA/CD32a	Fc gamma RIIIA
FGFR1 alpha (IIIc)	FGFR2 alpha (IIIc)	FGFR3	FGFR4	Flt-3/Flk-2	GITR/TNFRSF18
Glypican-3	gp130	Guanylyl Cyclase C	Hepassocin/FGL1	HVEM/TNFRSF14	ICAM-1/CD54
ICOS	IFN-gamma R1/CD119	IgG1	IL-1 RAcP/IL-1 R3	IL-1 Rrp2/IL-1R6	IL-2 R beta
IL-3R alpha	IL-4 R alpha	IL-5R alpha/CD125	IL-6 R alpha	IL-7 R alpha/CD127	IL-10 R alpha
IL-12 R beta 1	IL-12 R beta 2	IL-13 R alpha 1	IL-15 R alpha	IL-17RA/IL-17R	IL-18 Bpa
IL-18 R alpha/IL-1 R5	IL-18 R beta/IL-1 R7	IL-21 R	IL-23R	IL-31RA	Jagged 1
LAG-3	LAIR1	LAIR2	LILRB2/CD85d/ILT4	Lymphotoxin alpha1/beta2	M-CSF R/CD115
Mer	Mesothelin	MICA	MSPR/Ron	MUC-1	MuSK
Nectin-1	Nectin-2/CD112	Nectin-4	Neuropilin-1	NKp30	NKp44/NCR2
Osteoactivin/GPNMB	OX40/TNFRSF4	PD-1	PD-L1/B7-H1	PD-L2/B7-DC	PDGF R alpha
PDGF R beta	PILR-alpha	PILR-beta	PSMA/FOLH1/NAALADase I	ROR1	Siglec-2/CD22
Siglec-3/CD33	Siglec-10	SIRP alpha/CD172a	SARS-CoV-2 Spike	SARS-CoV-2 Spike RBD	SARS-CoV-2 Spike S1
ST2/IL-33 R	Syndecan-1/CD138	TGF-beta 1	TGF-beta RI	TGF-beta RII	Tie-2
TIGIT (T103)	TIM-1/KIM-1/ HAVCR	TIM-3	TNF-alpha	TNF RI/TNFRSF1A	TNF RII/TNFRSF1B
TRANCE/RANK L	TREM-1	TREM2	TSLP R	uPAR	ULBP-2
VEGF 165	VEGFR2/KDR/ Flk-1	VEGFR3/Flt-4	VISTA/B7-H5/PD-1H	VSIG3	VSIG4
VSTM2A	VSTM2B

Browse All Avi-tag Proteins

Advantages of Amine-labeled and Sugar-labeled Biotinylated Proteins

1. High signal strength. Proteins typically average multiple biotins per molecule making them an excellent choice when high signal strength is important.
2. Equivalent bioactivity. Biotinylated proteins are rigorously tested to ensure that they exhibit the same level of bioactivity as the unlabeled protein.
3. Lot-to-lot consistency. Each new lot is tested side-by-side with previous lots and with a master lot to ensure high lot-to-lot consistency.

Amine-labeled and Sugar-labeled Biotinylated Proteins – Products by Molecule

Biotinylated protein features:

Equivalent Bioactivity

Consistent bioactivity between biotinylated and non-biotinylated proteins

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Both Biotinylated Recombinant Human PD-L1/B7-H1 Fc Avi-tag and unlabeled Recombinant Human PD-L1/B7-H1 inhibit anti-CD3 antibody-induced IL-2 secretion in human T lymphocytes. The similarity in activity highlights that the biotinylated Avi-tag protein is fully functional.	Both Biotinylated Recombinant Human VEGF 165 (Catalog # BT293) and unlabeled Recombinant Human VEGF 165 (Catalog # 293-VE) stimulate HUVEC human umbilical vein endothelial cell proliferation. The ED₅₀ for this effect is 1-6 ng/mL. The similarity in activity highlights that the biotinylated protein is fully functional.	Both Biotinylated Recombinant Human TNF-alpha (Catalog # BT210) and unlabeled Recombinant Human TNF-alpha (Catalog # 210-TA) promotes cytotoxicity in L‑929 mouse fibroblast cells in the presence of the metabolic inhibitor actinomycin D. The ED₅₀ for this effect is 25-100 pg/mL. The similarity in activity highlights that the biotinylated protein is fully functional.

Binding activity

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When 500 ng/mL of Biotinylated Recombinant Human PD-1 His-tag Avi-tag protein is immobilized onto Streptavidin coated plate (Catalog # CP004), it binds to Recombinant Human PD-L1/B7-H1 Fc Chimera (Catalog # 156-B7) with an ED₅₀ of 1.2-7.2 ng/mL.	When Recombinant Human APRIL/TNFSF13 (Catalog # 5860-AP) is immobilized at 0.1 µg/mL, Recombinant Human BCMA/TNFRSF17 Fc Chimera Avi-tag (Catalog # AVI193) binds with an ED₅₀ of 0.3-1.8 ng/mL.	When Recombinant Human VSIG3 Fc Chimera (Catalog # 9229-VS) is coated at 5 μg/mL, Biotinylated Recombinant Human VISTA/B7-H5/PD-1H Fc Chimera Avi-tag (Catalog # AVI7126) binds with an ED₅₀ of 0.5-3 μg/mL.

Lot-to-lot consistency

When Recombinant Human PD-1 (Catalog #1086-PD) is coated at1 μg/mL, Biotinylated Recombinant Human PD-L1/B7-H1 Avi-tag (Catalog # AVI156) binds with an ED50 of 8-48 ng/mL.

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Three independent lots of B7-H1/PD-L1 have near identical bioactivity. When Recombinant Human PD-1 (Catalog #1086-PD) is coated at1 μg/mL, Biotinylated Recombinant Human PD-L1/B7-H1 Avi-tag (Catalog # AVI156) binds with an ED₅₀ of 8-48 ng/mL.

Surface Plasmon Resonance (SPR)

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Immobilized CD155/PVR-Fc Avi-tag (Catalog # AVI9174) bound to streptavidin CM5 chip binds to TIGIT-Fc (Catalog # 7898-TGB) with an affinity constant of 25.4 nM. Experiment performed on Biacore T200, GE Healthcare. For more information on using Avi-tag proteins in SPR, download the application note.

About Biotinylated Proteins

Biotinylated proteins are powerful tools used in a wide variety of assay formats, including immunoprecipitation, flow cytometry, immunoassays, biopanning, and surface plasmon resonance. Historically, individual labs have made their own biotinylated proteins in small batches. However, often times researchers encounter protein-specific technical challenges and high variability leading to inconsistent results.

What is Avi-tag?

Avi-tag Biotinylated Proteins are proteins that feature biotinylation at a single site contained within the Avi-tag, a unique 15 amino acid peptide. The DNA sequence coding for the Avi-tag is inserted during cloning and contained in the final expression vector construct. Biotinylation of the Avi-tag is enzymatically added by the E. coli biotin ligase BirA. This results in a single biotin molecule covalently attached to the lysine residue within the Avi-tag. The Avi-tag sequence is Gly-Leu-Asn-Asp-Ile-Phe-Glu-Ala-Gln-Lys-Ile-Glu-Trp-His-Glu.

ACE-2	AGE-BSA	Angiopoietin-1	Angiopoietin-2	Angiopoietin-like 3, N-term	Angiopoietin-like 4
Angiopoietin-like 7	B7-H3	B7-H6	B7-H7	BMP-7	Dkk-1
Ephrin-A1	Ephrin-A2	Ephrin-A3	Ephrin-A4	Ephrin-A5	Ephrin-B1
Ephrin-B2	Ephrin-B3	Frizzled-8	HGF	ICOS	IL-2
IL-6	IL-17A	IL-17A/F Heterodimer	IL-21	IL-27	LAG-3
LIF	LILRB2/CD85d/ILT4 BT2078	M-CSF	PD-1	PD-L1	PD-L2
PDGF-BB	R-Spondin 1	SIRP-alpha	SARS-CoV-2 Spike Protein	SARS-CoV-2 Spike RBD	SCF/c-kit
TGF-beta 1	TNF-alpha	Ubiquitin	VEGF	Viral B8R	Viral B18R
VISTA	VSIG3	Wnt-3a	Wnt-5a