Ligand Specificity of Human Surfactant Protein D

Crouch, Erika C.; Tu, Yizheng; Briner, David M.; McDonald, Barbara; Smith, Kenneth Michael; Holmskov, Uffe; Hartshorn, Kevan L.

doi:10.1074/jbc.m413932200

Cited by 48 publications

(31 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Expression, Purification, and Biochemical Characterization of Trimeric NeckϩCRDs-The design, expression, and characterization of N-terminal-tagged, trimeric human NCRD fusion proteins has been previously described (9). For these studies, we performed site-directed substitutions at position 335 within the CRD, as defined by numbering of the full-length protein: alanine (F335A), leucine (F335L), tyrosine (F335Y), and tryptophan (F335W) (Fig.…”

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

“…After refolding and oligomerization, the fusion proteins were purified by nickel affinity chromatography and trimers were isolated by gel filtration (9). Protein concentrations were determined using the bicinchoninic acid assay with bovine serum albumin as standard.…”

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

“…Competent cells were transformed with wild-type or mutant constructs in pET-30a(ϩ) vector, and expressed proteins were isolated from inclusion bodies (9). After refolding and oligomerization, the fusion proteins were purified by nickel affinity chromatography and trimers were isolated by gel filtration (9).…”

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

“…The binding of trimeric NCRDs to yeast mannan was examined as previously described (9). For competition assays, proteins were added to wells in the presence of various concentrations of competing inhibitors.…”

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

See 3 more Smart Citations

Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D

Crouch

McDonald

Smith

et al. 2006

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Surfactant protein D (SP-D) is an innate immune effector that contributes to antimicrobial host defense and immune regulation. Interactions of SP-D with microorganisms and organic antigens involve binding of glycoconjugates to the C-type lectin carbohydrate recognition domain (CRD). Surfactant Protein D (SP-D)2 is a collagenous C-type lectin (collectin) that contributes to antimicrobial host defense and immune regulation in the lung and certain extrapulmonary tissues (1-4). Like many other effectors of innate immunity, SP-D is a pattern recognition molecule with a variety of potential ligands, including microorganisms, organic particulate antigens, and apoptotic cells. However, there is also evidence that SP-D contributes to pulmonary surfactant homeostasis, in part by regulating the organization and epithelial uptake of surfactant lipids (5).SP-D is a member of a family of collectins, or collagenous C-type lectins (6). In mammals, this family also includes surfactant protein A (SP-A) and serum mannose binding lectin. Like most other collectins, SP-D is assembled as multimeric complexes of trimeric subunits, or as trimers (7). Each trimer includes an N-terminal cross-linking and collagen domain; a trimeric neck domain; and a C-terminal trimeric array of C-type carbohydrate recognition domains (CRDs).Crystallographic studies of trimeric human SP-D neckϩCRD domains have shown that maltose, a preferred saccharide ligand, binds to calcium via the vicinal 3-and 4-OH groups of the non-reducing glucose, previously designated calcium ion 1 and glucose 1 (Glc1), respectively (8). These interactions are further stabilized by hydrogen bonding of Glc1 to amino acid side chains that also coordinate with calcium ion 1.The present studies were prompted by the initial observation that p-nitrophenyl-␣-D-maltoside (p-NP-maltoside) is a potent inhibitor of SP-D binding to mannan. We hypothesized that there were interactions of the aromatic substituent with a hydrophobic or aromatic group in proximity to calcium ion 1. Preliminary modeling focused our attention on phenylalanine 335 (Phe-335) (Fig. 1A). To test our hypothesis, we used a functional, trimeric neckϩCRD (NCRD) fusion protein containing the neckϩCRD domains of human SP-D (Fig. 1, B-D) (9) and introduced site-directed substitutions at position 335. We also examined the crystal structures of purified human trimeric neckϩCRD complexed with the p-nitrophenyl-maltoside and maltotriose.

show abstract

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

Section: The P-nitrophenyl-␣-d-maltoside (Number 487542) Was From Emdmentioning

confidence: 99%

See 2 more Smart Citations

Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D

Crouch

McDonald

Smith

et al. 2006

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…This is in contrast to the effects observed in previous studies in which the bovine collectin CL-43-specific "RAK" motif was inserted near the conserved groove region of hSP-D, similar to the SGA modification of hSP-D as performed in this study. Although insertion of RAK into hSP-D substantially increased binding affinity for mannose-containing viral glycoconjugates (44), insertion of the SGA loop apparently induced changes in the groove region of the CRD such that viral carbohydrate recognition by RhSP-D-SGA was impaired. Obviously, it is complicated to predict the exact conformational effects of insertions within loop regions and characterization of the crystal structure of pSP-D complexed with ligand will be required to learn more about the role of the SGA loop region in pSP-D for glycan recognition.…”

Section: N-glycan-mediated Activity Of Sp-d Against Iav Requiresmentioning

confidence: 99%