Avidin, synthesized in the hen oviduct, is a glycoprotein of MW 68,000 daltons which occupies about 0.05% (w/w) of the total protein content of the hen egg white.
The great affinity of Avidin for d-biotin, vitamin H (k_d= 10^-15M) results in a great number of applications in biochemistry (immunoassays, receptor and histochemical studies, bacteriophage inhibitions... (1,2).

DEFINITION

One unit of avidin activity is definied as the amount of protein which will bind 1 µg of d-biotin or of HABA (4-hydroxyazobenzene-2'-carboxylic acid). See Biochem. J.; 89, 599 (1963).

AVIDIN, NATIVE (Code: AVIP-N)

Native avidin is a tetrameric protein composed of four identical subunits. Each subunit is glycosylated at 17-Asparagine and has one binding site for d-biotin.
The highest activity of Avidin highly purified, is found to be 13-14 units per mg of protein.
The isoelectric point of native Avidin is 10.5.
The basic glycoprotein nature of native Avidin results in some non-specific binding observed in different studies (3).
Streptavidin, a neutral bacterial analog of Avidin which is non- glycosylated and obtained from Streptomyces avidinii, does not show this non-specific binding due to the native Avidin.
However, contrary to Avidin, Streptavidin contains a sequence highly homologous to a segment of fibronectin. Recent studies have demonstrated that the non-specific binding of streptavidin is due to the strong interactions of this sequence with cell surface receptors (4).

AVIDIN, NATIVE pI neutre (Code: AVIP-NNeutral pI) New!

This is a native Avidin with neutral isoelectric point.
Its activity is 13-14 units per mg of protein.

AVIDIN, DEGLYCOSYLATED pI 10.5 (Code: AVIP-DG-10.5)

This modified Avidin, obtained by the total removal of carbohydrate moieties of the native Avidin, is not recognized by lectins or other carbohydrate binding proteins.
Its isoelectric point remains at 10.5.
Its activity is 13-14 units per mg of protein.

AVIDIN, DEGLYCOSYLATED pI neutre (Code: AVIP-DG-Neutral pI)

That is a non-glycosylated Avidin with neutral isoelectric point.
Avidin, deglycosylated neutral pI does not present the non-specific binding mentioned above.
Its activity is 13-14 units per mg of protein.

SOLUBILITY OF AVIDINS

Avidin, native or modified is highly soluble in water or salt solution at physiological pH (7.5-8.0): 50 mg of Avidin per ml of solution.

STABILITY OF AVIDINS

Avidin, native or modified is very stable against heat, pH changes and chaotropic reagents (5). The Avidin solution is stable for weeks or a month at 4°C.

References:

(1) N.M. GREEN; Adv. Protein Chem. 29, 85-133 (1975).
(2) M. WILCHECK and E.A. BAYER; Methods in Enzymology: Avidin-Biotin Technology, Vol. 184 (1990).
(3) R.C. BRUCH and H.B. WHITE; Biochemistry 21, 5334-5341 (1982).
(4) R. ALON et al.; Biochem. Biophys. Res. Commun. 170, 1236-1241 (1990).
(5) J.W.DONOVAN and K.D. ROSS; Biochemistry 12, 512 (1973).

ORDERING INFORMATION

Complete technical data sheet provided with the order.

Product code	Product name	Package	*Price in EUR
AVIP-N	Avidin, Native, pI 10.5 Lyophilized powder	100 mg 10 x 100 mg	240.00 2400 x 0.8 = 1920.00
New! AVIP- NNeutral pI	Native Avidin, pI neutre Lyophilized powder	100 mg 10 x 100 mg	Promotion 300.00 Instead of 350.00 3000 x 0.8 = 2400.00
AVIP-DG-10.5	Deglycosylated Avidin, pI 10.5 Lyophilized powder	100 mg 10 x 100 mg	400.00 4000 x 0.8 = 3200.00
AVIP-DG-Neutral pI	Deglycosylated Avidin, pI neutre Lyophilized powder	100 mg	450.00

* All prices are FOB Liège.
Bulk quantities are available.

Shipment at room temperature, storage at 4°C upon arrival