| Structural highlights
6w9g is a 9 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 1.82Å |
| Ligands: | , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Disease
CD40L_HUMAN Defects in CD40LG are the cause of X-linked immunodeficiency with hyper-IgM type 1 (HIGM1) [MIM:308230; also known as X-linked hyper IgM syndrome (XHIM). HIGM1 is an immunoglobulin isotype switch defect characterized by elevated concentrations of serum IgM and decreased amounts of all other isotypes. Affected males present at an early age (usually within the first year of life) recurrent bacterial and opportunistic infections, including Pneumocystis carinii pneumonia and intractable diarrhea due to cryptosporidium infection. Despite substitution treatment with intravenous immunoglobulin, the overall prognosis is rather poor, with a death rate of about 10% before adolescence.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Function
CD40L_HUMAN Mediates B-cell proliferation in the absence of co-stimulus as well as IgE production in the presence of IL-4. Involved in immunoglobulin class switching.[11] Release of soluble CD40L from platelets is partially regulated by GP IIb/IIIa, actin polymerization, and an matrix metalloproteinases (MMP) inhibitor-sensitive pathway.[12]
Publication Abstract from PubMed
Genetically encoded fluorescent noncanonical amino acids (fNCAAs) could be used to develop novel fluorescent sensors of protein function. Previous efforts toward this goal have been limited by the lack of extensive physicochemical and structural characterizations of protein-based sensors containing fNCAAs. Here, we report the steady-state spectroscopic properties and first structural analyses of an fNCAA-containing Fab fragment of the 5c8 antibody, which binds human CD40L. A previously reported 5c8 variant in which the light chain residue Ile(L)98 is replaced with the fNCAA l-(7-hydroxycoumarin-4-yl)ethylglycine (7-HCAA) exhibits a 1.7-fold increase in fluorescence upon antigen binding. Determination and comparison of the apparent pKas of 7-HCAA in the unbound and bound forms indicate that the observed increase in fluorescence is not the result of perturbations in pKa. Crystal structures of the fNCAA-containing Fab in the apo and bound forms reveal interactions between the 7-HCAA side chain and surrounding residues that are disrupted upon antigen binding. This structural characterization not only provides insight into the manner in which protein environments can modulate the fluorescence properties of 7-HCAA but also could serve as a starting point for the rational design of new fluorescent protein-based reporters of protein function.
Structural Insights into How Protein Environments Tune the Spectroscopic Properties of a Noncanonical Amino Acid Fluorophore.,Henderson JN, Simmons CR, Fahmi NE, Jeffs JW, Borges CR, Mills JH Biochemistry. 2020 Sep 22;59(37):3401-3410. doi: 10.1021/acs.biochem.0c00474., Epub 2020 Sep 3. PMID:32845612[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Aruffo A, Farrington M, Hollenbaugh D, Li X, Milatovich A, Nonoyama S, Bajorath J, Grosmaire LS, Stenkamp R, Neubauer M, et al.. The CD40 ligand, gp39, is defective in activated T cells from patients with X-linked hyper-IgM syndrome. Cell. 1993 Jan 29;72(2):291-300. PMID:7678782
- ↑ Korthauer U, Graf D, Mages HW, Briere F, Padayachee M, Malcolm S, Ugazio AG, Notarangelo LD, Levinsky RJ, Kroczek RA. Defective expression of T-cell CD40 ligand causes X-linked immunodeficiency with hyper-IgM. Nature. 1993 Feb 11;361(6412):539-41. PMID:7679206 doi:http://dx.doi.org/10.1038/361539a0
- ↑ DiSanto JP, Bonnefoy JY, Gauchat JF, Fischer A, de Saint Basile G. CD40 ligand mutations in x-linked immunodeficiency with hyper-IgM. Nature. 1993 Feb 11;361(6412):541-3. PMID:8094231 doi:http://dx.doi.org/10.1038/361541a0
- ↑ Allen RC, Armitage RJ, Conley ME, Rosenblatt H, Jenkins NA, Copeland NG, Bedell MA, Edelhoff S, Disteche CM, Simoneaux DK, et al.. CD40 ligand gene defects responsible for X-linked hyper-IgM syndrome. Science. 1993 Feb 12;259(5097):990-3. PMID:7679801
- ↑ Macchi P, Villa A, Strina D, Sacco MG, Morali F, Brugnoni D, Giliani S, Mantuano E, Fasth A, Andersson B, et al.. Characterization of nine novel mutations in the CD40 ligand gene in patients with X-linked hyper IgM syndrome of various ancestry. Am J Hum Genet. 1995 Apr;56(4):898-906. PMID:7717401
- ↑ Saiki O, Tanaka T, Wada Y, Uda H, Inoue A, Katada Y, Izeki M, Iwata M, Nunoi H, Matsuda I, et al.. Signaling through CD40 rescues IgE but not IgG or IgA secretion in X-linked immunodeficiency with hyper-IgM. J Clin Invest. 1995 Feb;95(2):510-4. PMID:7532185 doi:http://dx.doi.org/10.1172/JCI117692
- ↑ Katz F, Hinshelwood S, Rutland P, Jones A, Kinnon C, Morgan G. Mutation analysis in CD40 ligand deficiency leading to X-linked hypogammaglobulinemia with hyper IgM syndrome. Hum Mutat. 1996;8(3):223-8. PMID:8889581 doi:<223::AID-HUMU5>3.0.CO;2-A 10.1002/(SICI)1098-1004(1996)8:3<223::AID-HUMU5>3.0.CO;2-A
- ↑ Lin Q, Rohrer J, Allen RC, Larche M, Greene JM, Shigeoka AO, Gatti RA, Derauf DC, Belmont JW, Conley ME. A single strand conformation polymorphism study of CD40 ligand. Efficient mutation analysis and carrier detection for X-linked hyper IgM syndrome. J Clin Invest. 1996 Jan 1;97(1):196-201. PMID:8550833 doi:http://dx.doi.org/10.1172/JCI118389
- ↑ Nonoyama S, Shimadzu M, Toru H, Seyama K, Nunoi H, Neubauer M, Yata J, Och HD. Mutations of the CD40 ligand gene in 13 Japanese patients with X-linked hyper-IgM syndrome. Hum Genet. 1997 May;99(5):624-7. PMID:9150729
- ↑ Seyama K, Nonoyama S, Gangsaas I, Hollenbaugh D, Pabst HF, Aruffo A, Ochs HD. Mutations of the CD40 ligand gene and its effect on CD40 ligand expression in patients with X-linked hyper IgM syndrome. Blood. 1998 Oct 1;92(7):2421-34. PMID:9746782
- ↑ Furman MI, Krueger LA, Linden MD, Barnard MR, Frelinger AL 3rd, Michelson AD. Release of soluble CD40L from platelets is regulated by glycoprotein IIb/IIIa and actin polymerization. J Am Coll Cardiol. 2004 Jun 16;43(12):2319-25. PMID:15193700 doi:10.1016/j.jacc.2003.12.055
- ↑ Furman MI, Krueger LA, Linden MD, Barnard MR, Frelinger AL 3rd, Michelson AD. Release of soluble CD40L from platelets is regulated by glycoprotein IIb/IIIa and actin polymerization. J Am Coll Cardiol. 2004 Jun 16;43(12):2319-25. PMID:15193700 doi:10.1016/j.jacc.2003.12.055
- ↑ Henderson JN, Simmons CR, Fahmi NE, Jeffs JW, Borges CR, Mills JH. Structural Insights into How Protein Environments Tune the Spectroscopic Properties of a Noncanonical Amino Acid Fluorophore. Biochemistry. 2020 Sep 22;59(37):3401-3410. doi: 10.1021/acs.biochem.0c00474., Epub 2020 Sep 3. PMID:32845612 doi:http://dx.doi.org/10.1021/acs.biochem.0c00474
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