LAMP1 (Lysosomal Associated Membrane Protein 1) is a protein primarily associated with the lysosomal membrane. In a typical cell LAMP1 is associated with spherical vesicles located next to the nucleus and the microtubule organizing center (1). LAMP1 is found on the cell surface of lymphocytes undergoing degranulation, a process in which cytoplasmic vesicles fuse with the plasma membrane, and this phenomena resulted in discovery of LAMP1 as a CD protein. The LAMP1 protein has a large N-terminal region which is inside the lysosome, hence topologically external to the cell, which is often referred to as the lumenal domain (2). The lumenal domain consists of two homologous globular segments separated by a proline rich sequence. Next there is a single membrane spanning domain and a short 11 amino acid C-terminal cytoplasmic tail. This tail region contains, at the extreme C-terminus, a so-called YXXI motif which is responsible for the sorting of the intact molecule to the endosome and lysozome, where Y = tyrosine, I = isoleucine and X = almost any amino acid (3). This motif is found in several other lysosomal proteins, where it functions in the same way. There are 417 amino acids in the human LAMP1 molecule, giving a native molecular weight of 44.8kDa. However the N-terminal lumenal segment of LAMP1 is very heavily and variably glycosylated due to the presence of 18 N-linked glycosylation sites, so that on SDS-PAGE and on Western blots the protein runs as a diffuse band at 90-120kDa. Antibodies to LAMP1 are excellent markers of lysosomes, though some LAMP1 may also be seen on late endosomes and on the plasma membrane.

Applications: Western Blotting (WB), Immunocytochemistry (IC), Flow Cytometry. A dilution of 1:5,000 - 1:10,000 is recommended for WB. A dilution of 1:1,000 - 1:2,000 is recommended for IC. Use ~2ug per 10^6 cells for Flow Cytometry. Biosensis recommends optimal dilutions/concentrations should be determined by the end user.

Type: Primary
Antigen: LAMP1
Clonality: Monoclonal
Clone: 5H6
Conjugation: Unconjugated
Epitope:
Host: Mouse
Isotype: IgG1
Reactivity: Human