Recombinant Human SR-AI/MSR Protein, CF

• Reactivity: Hu
• Applications: Binding Activity
• Format: Carrier-Free

Recombinant Human SR-AI/MSR Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA. Immobilized Recombinant Human SR‑AI/MSR at 5 µg/mL (100 µL/well) can bind biotinylated advanced glycation endproducts of bovine serum albumin (AGE-BSA) with a linear range of 6-400 ng/mL.
• Source: Mouse myeloma cell line, NS0-derived human SR-AI/MSR protein
  Lys77-Leu451, with an N-terminal 9-His tag
• Accession #: P21757
• N-terminal Sequence: His
• Protein/Peptide Type: Recombinant Proteins
• Gene: MSR1
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Binding Activity
• Theoretical MW: 42.5 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 65-72 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 100 μg/mL in sterile PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human SR-AI/MSR Protein, CF

• CD204 antigen
• CD204
• Macrophage acetylated LDL receptor I and II
• macrophage scavenger receptor 1
• macrophage scavenger receptor type III
• MSR1
• phSR1
• phSR2
• SCARA1
• SCARA1macrophage scavenger receptor types I and II
• Scavenger receptor class A member 1
• scavenger receptor class A, member 1
• SR-A
• SRAI
• SR-AI

Background

The type I class A macrophage scavenger receptor (SR-AI; also MSR-AI) is a 70-80 kDa protein that belongs to an ever expanding family of transmembrane molecules collectively referred to as scavenger receptors (1 - 3). Receptors of this family contain characteristic extracellular domains and bind to a series of generally unrelated, but negatively-charged/polyanionic ligands (1, 3). Human SR-AI is a type II transmembrane glycoprotein that is 451 amino acids (aa) in length. It contains a 50 aa cytoplasmic tail, a 26 aa transmembrane segment and a 375 aa extracellular region (4, 5). The extracellular region contains four definitive domains, with a membrane proximal spacer of 33 aa, an alpha -helical coiled-coil domain of 163 aa, a collagen-like domain of 69 aa, and a cysteine-rich C-terminus of 110 aa (4, 6). The cysteine-rich domain (CRD) forms three intrachain disulfide bonds (7). The functional form of the molecule is a 220 - 230 kDa membrane-associated trimer that, in human, apparently has two disulfide bonded chains and a third noncovalently associated subunit (8, 9). Human extracellular region is 73% and 72% aa identical to bovine and mouse SR-AI extracellular region, respectively. The human gene for SR-A gives rise to three isoforms; the I isoform of 451 aa, the II isoform of 358 aa, and the III isoform of 388 aa (4, 5, 10). All are equal through the first 344 aa which includes the cytoplasmic tail through the collagenous domain. Isoform II (SR-AII) shows a severe truncation of the CRD, but is expressed on the cell surface. Isoform III (SR-AIII) has a modest truncation of the CRD, and cannot be expressed on the cell surface. Their functions are unknown. However, relative to SR-AI, SR-AII is known to show differential sensitivity to LPS and receptor binding to gram-negative bacteria,(9, 11) while SR-AIII is known to be a dominant-negative isoform (10). SR-AIII may achieve this by either heterotrimerizing with SR-AI, or simply eliminating the production of SR-AI mRNA.

1. Platt, N. and S. Gordon (2001) J. Clin. Invest. 108:649.
2. Linton, M.F. and S. Fazio (2001) Curr. Opin. Lipidol. 12:489.
3. Platt, N. and S. Gordon (1998) Chem. Biol. 5:R193.
4. Matsumoto, A. et al. (1990) Proc. Natl. Acad. Sci. USA 87:9133.
5. Emi, M. et al. (1993) J. Biol. Chem. 268:2120.
6. Naito, M. et al. (1992) Am. J. Pathol. 141:591.
7. Resnick, D. et al. (1996) J. Biol. Chem. 271:26924.
8. Ashkenas, J. et al. (1993) J. Lipid Res. 34:983.
9. Penman, M. et al. (1991) J. Biol. Chem. 266:23985.
10. Gough, P.J. et al. (1998) J. Lipid Res. 39:531.
11. Peiser, L. et al. (2000) Inf. Immun. 68:1953.

Publications for SR-AI/MSR (2708-MS)(3)

Publications using 2708-MS

• T Kamata, TY So, Q Ahmed, S Giblett, B Patel, J Luo, R Reddel, C Pritchard Fibroblast-Derived STC-1 Modulates Tumor-Associated Macrophages and Lung Adenocarcinoma Development Cell Rep, 2020-06-23;31(12):107802. 2020-06-23 [PMID: 32579928] (ELISA Development, Human)
• Raycroft MT, Harvey BP, Bruck MJ, Mamula MJ Inhibition of antigen trafficking through scavenger receptor A. J. Biol. Chem., 2012-01-03;287(8):5310-6. 2012-01-03 [PMID: 22215667] (ELISA (Capture))
• Chen XW, Shen Y, Sun CY, Wu FX, Chen Y, Yang CD Anti-class a scavenger receptor autoantibodies from systemic lupus erythematosus patients impair phagocytic clearance of apoptotic cells by macrophages in vitro. Arthritis Res. Ther., 2011-01-31;13(1):R9. 2011-01-31 [PMID: 21281474] (ELISA (Capture), Human)

Bioinformatics

• Gene Symbol: MSR1
• Uniprot:
  • P21757()