Top

Laminin Rabbit Polyclonal Antibody

Cat Number: AB- 83936
Conjugate: Unconjugated
Size: 100 ug
Clone: POLY
Concentration: 1mg/ml
Host: Rabbit
Isotype: IgG
Immunogen: Laminin 111 from mouse EHS sarcoma cells obtained from Sigma-Aldrich.
Reactivity: Human, Rat, Mouse
Applications:

Western Blot: 1:5,000
Immunofluorescence: 1:1,000-5,000
Immunocytochemistry: 1:1,000-5,000
Immunohistochemistry: 1:1,000-5,000

Molecular Weight: 440kDa, 220kDa, 158kDa
Purification: Aff. Pur.
Background:

Laminins are high-molecular weight proteins and major components of the extracellular matrix. They are an important part of the basal lamina a protein network typically separating cells and tissues of different embryonic origin. Laminin was first isolated biochemically from Engelbreth-Holm-Swarm (EHS) mouse sarcoma cells, a cell line which produces large amounts of extracellular matrix material (1,2). Laminins are heterotrimeric proteins that contain one of five α-chains, one of three β-chains and one of three γ-chains (3-4). The EHS sarcoma cell derived laminin was originally named laminin 1, composed of α1β1γ1 polypeptides (5), though a later nomenclature named this form laminin 111, the numbers indicating the content of α, β and γ gene products (6). The distribution of the different laminin isoforms is developmental time and tissue-specific and laminin-111 expressed in the embryonic epithelium, but is also expressed in adult kidney, liver, testis, ovaries and brain blood vessels (7). Genetic ablation of laminin-111 results in embryonic death (8), and point mutations in the human α1 gene resulted in Poretti Boltshauser Syndrome, a rare disorder associated with cerebellar abnormalities, ataxia, cognitive problems and other issues. Injection of laminin–111 into muscle appeared to be a promising therapy in a mouse model Duchenne muscular dystrophy (DMD, 9). However transgenic overexpression of the laminin α1 protein appeared to have no beneficial affect also in a mouse DMD model (10).
The Laminin antibody was made against laminin 111 isolated biochemically from mouse Engelbreth-Holm-Swarm (EHS) sarcoma cells (1,2). The antibody recognizes the several different laminin polypeptides on western blots and is a very useful reagent for visualizing basal lamina in mature and developing tissues. It is particularly useful in the CNS, allowing visualization of the basal lamina of endothelia, an important part of the blood brain barrier. Mouse select image above left for larger view.

Form: Liquid
Buffer: Affinity purified antibody at 1mg/mL in 50% PBS, 50% glycerol plus 5mM NaN3
Storage: Storage for short term at 4°C recommended, for longer term at -20°C.
AB-83936-1

Western blot analysis of different tissue lysates using rabbit pAb to laminin, dilution 1:5,000 in green: [1] protein standard (red), [2] rat brain, [3] rat spinal cord, and [4] cow spinal cord lysate. The strong band above the 280kDa mark corresponds to full length laminin proteins. Smaller proteolytic fragments of laminin are also detected with this antibody.

AB-83936-2

Immunohistological analysis of brain stem section stained with rabbit pAb to laminin, dilution 1:1,000 in red, and costained with chicken pAb to myelin basic protein (MBP), dilution 1:5,000 in green. The blue is DAPI staining of nuclear DNA. Following transcardial perfusion of rat with 4% paraformaldehyde, brain was post fixed for 24 hours, cut to 45μM, and free-floating sections were stained with the above antibodies. The laminin antibody is an excellent marker of basement membranes surrounding blood vessels, while the MBP antibody stains the myelin sheathes around axons.

References:

1. Timpl R, et al. Laminin–a glycoprotein from basement membranes. J. Biol. Chem. 254:9933-7 (1979).
2. Kleinman HK, et al. Isolation and Characterization of Type IV Procollagen, Laminin, and Heparan Sulfate Proteoglycan from the EHS Sarcoma. Biochemistry 21:6188-93 (1982).
3. Colognato H, Yurchenco PD. Form and function: the laminin family of heterotrimers.Dev. Dyn. 218:213-34 (2000).
4. Durbeej M, Laminins. Cell Tiss. Res. 339:259-268 (2010).
5. Burgeson RE, et al. A new nomenclature for the laminins. Matrix Biology 14:209-11 (1994).
6. Aumailley M, et al. A simplified laminin nomenclature. Matrix Biology 24:326-332 (2005).
7. Ekblom M, et al. Laminin isoforms and epithelial development. Ann. NY Acad. Sci. 857:194-211 (1998).
8. Alpy F, et al. Generation of a conditionally null allele of the laminin alpha1 gene. Genesis 43:59-70 (2005).
9. Rooney JE, Gurpur PB, Burkin DJ. Laminin-111 protein therapy prevents muscle disease in the mdx mouse model for Duchenne muscular dystrophy. PNAS 106:7991-6 (2009).
10. Gawlik KI, Oliveira BM, Durbeej M. Transgenic Expression of Laminin α1 Chain Does Not Prevent Muscle Disease in the mdx Mouse Model for Duchenne Muscular Dystrophy. Am. J. Pathol. 178:1728-37 (2011).