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Title: Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands

Abstract

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). A trimeric fusion protein encoding the human neck+CRD (hNCRD) bound to the aromatic glycoside, p-nitrophenyl-alpha-D-maltoside, with nearly a log-fold higher affinity than maltose, the prototypical competitor. Maltotriose, which has the same linkage pattern as the maltoside, bound with intermediate affinity. Site-directed substitution of leucine for phenylalanine 335 (Phe335) decreased affinities for the maltoside and maltotriose without significantly altering the affinity for maltose or glucose, and substitution of tyrosine or tryptophan for leucine restored preferential binding to maltotriose and the maltoside. A mutant with alanine at this position failed to bind to mannan or maltose-substituted solid supports. Crystallographic analysis of the hNCRD complexed with maltotriose or p-nitrophenyl-maltoside showed stacking of the terminal glucose or nitrophenyl ring with the aromatic ring of Phe335. Our studies indicate that Phe335, which is evolutionarily conserved in all known SP-Ds, plays important - if not critical roles - in SP-D function.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
914065
Report Number(s):
BNL-78633-2007-JA
Journal ID: ISSN 0021-9258; JBCHA3; TRN: US0801514
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Biol. Chem.; Journal Volume: 281
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; AFFINITY; LIGANDS; MALTOSE; PROTEINS; SURFACTANTS; NSLS; national synchrotron light source

Citation Formats

Crouch,E., McDonald, B., Smith, K., Cararella, T., Seaton, B., and Head, J. Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands. United States: N. p., 2006. Web. doi:10.1074/jbc.M601749200.
Crouch,E., McDonald, B., Smith, K., Cararella, T., Seaton, B., & Head, J. Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands. United States. doi:10.1074/jbc.M601749200.
Crouch,E., McDonald, B., Smith, K., Cararella, T., Seaton, B., and Head, J. Sun . "Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands". United States. doi:10.1074/jbc.M601749200.
@article{osti_914065,
title = {Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands},
author = {Crouch,E. and McDonald, B. and Smith, K. and Cararella, T. and Seaton, B. and Head, J.},
abstractNote = {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). A trimeric fusion protein encoding the human neck+CRD (hNCRD) bound to the aromatic glycoside, p-nitrophenyl-alpha-D-maltoside, with nearly a log-fold higher affinity than maltose, the prototypical competitor. Maltotriose, which has the same linkage pattern as the maltoside, bound with intermediate affinity. Site-directed substitution of leucine for phenylalanine 335 (Phe335) decreased affinities for the maltoside and maltotriose without significantly altering the affinity for maltose or glucose, and substitution of tyrosine or tryptophan for leucine restored preferential binding to maltotriose and the maltoside. A mutant with alanine at this position failed to bind to mannan or maltose-substituted solid supports. Crystallographic analysis of the hNCRD complexed with maltotriose or p-nitrophenyl-maltoside showed stacking of the terminal glucose or nitrophenyl ring with the aromatic ring of Phe335. Our studies indicate that Phe335, which is evolutionarily conserved in all known SP-Ds, plays important - if not critical roles - in SP-D function.},
doi = {10.1074/jbc.M601749200},
journal = {J. Biol. Chem.},
number = ,
volume = 281,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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