Recombinant Human SP-D Protein, CF

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

Recombinant Human SP-D Protein, CF Summary

• Details of Functionality: Measured by its ability to bind fluorescein-conjugated E. coli Bioparticles. Kuan, S.F. et al. (1992) J. Clin. Invest. 90:97. The ED₅₀ for this effect is 0.5-3 µg/mL.
• Source: Mouse myeloma cell line, NS0-derived human SP-D protein
  Ala21-Phe375 (Glu22Gly)
• Accession #: P35247
• N-terminal Sequence: Ala21
• Structure / Form: Oligomer
• Protein/Peptide Type: Recombinant Proteins
• Gene: SFTPD
• 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: 35.4 kDa (monomer).
  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: 40-48 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 SP-D Protein, CF

• COLEC7collectin-7
• Collectin 7
• Collectin-7
• Lung surfactant protein D
• PSPD
• PSP-D
• SFTP4
• SFTP4pulmonary surfactant-associated protein D
• SFTPD
• SPD
• SP-D
• SP-Dpulmonary surfactant apoprotein
• surfactant protein D
• surfactant, pulmonary-associated protein D
• surfactant-associated protein, pulmonary 4

Background

SP-D (surfactant protein-D; also PSP-D) is a 43 kDa member of the collectin family of innate immune modulators. It is constitutively secreted by alveolar lining cells and epithelium associated with tubular structures. Its principal components consist of a collagen-like region and a C-terminal carbohydrate recognition domain (CRD), a structure that further places it in a subset of an expanded group of proteins termed defense collagens (1-4). Human SP-D is synthesized as a 375 amino acid (aa) precursor. It contains a 20 aa signal sequence and a 355 aa mature region. The mature molecule is characterized by the presence of a 25 aa N-terminal linking-region, a 177 aa hydroxyproline and hydroxylysine collagen-like domain, a 46 aa coiled-coil segment, and a 106 aa, C-terminal collectin-like C-type lectin domain (CRD) (5, 6). Two additional, potential isoforms exist. One shows a 13 aa N-terminal extension, while the other combines the N-terminal extension with a deletion of aa’s # 206-375. Mature human SP-D shares 75% and 78% aa identity with mouse and pig SP-D, respectively. Monomeric SP-D is unusual (3). The basic form of SP-D is that of a glycosylated, disulfide-linked 150 kDa trimer that generates an alpha -helical coiled-coil structure linked to a “head” of three symmetrical CRDs (4, 7). Each CRD recognizes the hydroxides of one monosaccharide (4). Trimerization allows for the discrimination of monosaccharide patterns specific to microbial pathogens (7). Typically, SP-D forms a higher-order 620 kDa, X-shaped dodecamer through disulfide bonds associated with the N-terminus (8). This allows for even finer discrimination of self vs. nonself carbohydrate patterns, and facilitates binding to complex antigens (8, 9). One polymorphism, a Met11-Thr11 transition in human, apparently precludes the formation of oligomers, potentially affecting the ability of affected individuals to interact with microorganisms (9, 10). Finally, SP-D is known to bind both SIRP alpha and the calreticulin/CD91 complex on macrophages. When the ratio of antigen/pathogen to available CRDs is low, antigen can be bound without occupying all available CRDs. The free CRDs will bind to SIRP alpha , generating a signal that downmodulates the inflammatory response. When virtually all CRDs are occupied by ligand, however, free CRDs are not available for SIRP alpha binding. Instead, the dodecamer is depicted to undergo a structural rearrangement, exposing the N-termini of all four linked trimers. This exposed terminus is known to bind to the calreticulin/CD91 complex, an event that initiates inflammation. Thus, it would appear that SP-D allows for a graded response to environmental challenge. SP-D provides a mechanism for the clearance of small antigenic insults without the need for a damaging inflammatory response (3).

1. Holmskov, U. et al. (2003) Annu. Rev. Immunol. 21:547.
2. Kishore, U. et al. (2006) Mol. Immunol. 43:1293.
3. Hartl, D. and M. Griese (2006) Eur. J. Clin. Invest. 36:423.
4. Sim, R.B. et al. (2006) Novartis Found Symp. 279:170.
5. Rust, K. et al. (1991) Arch. Biochem. Biophys. 290:116.
6. Lu, J. et al. (1992) Biochem. J. 284:795.
7. Hakansson, K. et al. (1999) Structure 7:225.
8. Ohya, M. et al. (2006) Biochemistry 45:8657.
9. Crouch, E.C. et al. (2006) Am. J. Respir. Cell Mol. Biol. 35:84.
10. Leth-Larsen, R. et al. (2005) J. Immunol. 174:1532.

Publications for SP-D (1920-SP)(8)

Publications using 1920-SP

• Dellière, S;Chauvin, C;Wong, SSW;Gressler, M;Possetti, V;Parente, R;Fontaine, T;Krüger, T;Kniemeyer, O;Bayry, J;Carvalho, A;Brakhage, AA;Inforzato, A;Latgé, JP;Aimanianda, V; Interplay between host humoral pattern recognition molecules controls undue immune responses against Aspergillus fumigatus Nature communications 2024-08-14 [PMID: 39138196] (Bioassay, Fungus - Aspergillus fumigatus)
• Hata, K;Tsubouchi, K;Suzuki, K;Eto, D;Ando, H;Yanagihara, T;Kan-O, K;Okamoto, I; Surfactant protein D prevents mucin overproduction in airway goblet cells via SIRP? Scientific reports 2024-01-20 [PMID: 38245585] (Cell Culture, Human)
• A Zoued, H Zhang, T Zhang, RT Giorgio, CJ Kuehl, B Fakoya, B Sit, MK Waldor Proteomic analysis of the host-pathogen interface in experimental cholera Nature Chemical Biology, 2021-10-21;17(11):1199-1208. 2021-10-21 [PMID: 34675415] (Bioassay, Vibrio cholerae)
• Y Tajima, M Tsuruta, H Hasegawa, K Okabayashi, T Ishida, M Yahagi, A Makino, K Koishikawa, S Akimoto, DD Sin, Y Kitagawa Association of surfactant protein D with pulmonary metastases from colon cancer Oncol Lett, 2020-10-05;20(6):322. 2020-10-05 [PMID: 33123238] (Bioassay, Human)
• S Sze Wah Wo, M Rani, E Dodagatta-, O Ibrahim-Gr, U Kishore, J Bayry, JP Latgé, A Sahu, T Madan, V Aimanianda Fungal melanin stimulates surfactant protein D-mediated opsonization of and host immune response to &lt;em&gt;Aspergillus fumigatus&lt;/em&gt; spores J. Biol. Chem., 2018-02-05;0(0):. 2018-02-05 [PMID: 29414772] (Bioassay, Human)
• Soltysiak K, van Schaik E, Samuel J Surfactant Protein D Binds to Coxiella burnetii and Results in a Decrease in Interactions with Murine Alveolar Macrophages. PLoS ONE, 2015-09-14;10(9):e0136699. 2015-09-14 [PMID: 26366725] (Bioassay, Bacteria - Coxiella burnetii, Bacteria - E. Coli)
• Bratcher , Preston, Weathington , Nathanie, Nick , Heidi J, Jackson , Patricia, Snelgrove , Robert J, Gaggar , Amit MMP-9 cleaves SP-D and abrogates its innate immune functions in vitro. PLoS ONE, 2012-07-30;7(7):e41881. 2012-07-30 [PMID: 22860023] (Enzyme Assay Substrate)
• Ruge CA, Schaefer UF, Herrmann J, Kirch J, Canadas O, Echaide M, Perez-Gil J, Casals C, Muller R, Lehr CM The interplay of lung surfactant proteins and lipids assimilates the macrophage clearance of nanoparticles. PLoS ONE, 2012-07-10;7(7):e40775. 2012-07-10 [PMID: 22802970] (Bioassay, Mouse)

Bioinformatics

• Gene Symbol: SFTPD
• Uniprot:
  • P35247()