PMID- 9038177
OWN - NLM
STAT- MEDLINE
DCOM- 19970415
LR  - 20211203
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 272
IP  - 9
DP  - 1997 Feb 28
TI  - Mechanism of Ca2+ and monosaccharide binding to a C-type carbohydrate-recognition 
      domain of the macrophage mannose receptor.
PG  - 5668-81
AB  - Site-directed mutagenesis has been used to identify residues that ligate Ca2+ and 
      sugar to the fourth C-type carbohydrate-recognition domain (CRD) of the 
      macrophage mannose receptor. CRD-4 is the only one of the eight CRDs of the 
      mannose receptor to exhibit detectable monosaccharide binding when expressed in 
      isolation, and it is central to ligand binding by the receptor. CRD-4 requires 
      two Ca2+ for sugar binding, like the CRD of rat serum mannose-binding protein 
      (MBP-A). Sequence comparisons between the two CRDs suggest that the binding site 
      for one Ca2+, which ligates directly to the bound sugar in MBP-A, is conserved in 
      CRD-4 but that the auxiliary Ca2+ binding site is not. Mutation of the four 
      residues at positions in CRD-4 equivalent to the auxiliary Ca2+ binding site in 
      MBP-A indicates that only one, Asn728, is involved in ligation of Ca2+. 
      Alanine-scanning mutagenesis was used to identify two other asparagine residues 
      and one glutamic acid residue that are probably involved in ligation of the 
      auxiliary Ca2+ to CRD-4. Sequence comparisons with other C-type CRDs suggest that 
      the proposed binding site for the auxiliary Ca2+ in CRD-4 of the mannose receptor 
      is unique. Evidence that the conserved Ca2+ in CRD-4 bridges between the protein 
      and bound sugar in a manner analogous to MBP-A was obtained by mutation of one of 
      the amino acid side chains at this site. Ring current shifts seen in the 1H NMR 
      spectra of methyl glycosides of mannose, GlcNAc, and fucose in the presence of 
      CRD-4 and site-directed mutagenesis indicate that a stacking interaction with 
      Tyr729 is also involved in binding of sugars to CRD-4. This interaction 
      contributes about 25% of the total free energy of binding to mannose. C-5 and C-6 
      of mannose interact with Tyr729, whereas C-2 of GlcNAc is closest to this 
      residue, indicating that these two sugars bind to CRD-4 in opposite orientations. 
      Sequence comparisons with other mannose/GlcNAc-specific C-type CRDs suggest that 
      use of a stacking interaction in the binding of these sugars is probably unique 
      to CRD-4 of the mannose receptor.
FAU - Mullin, N P
AU  - Mullin NP
AD  - Glycobiology Institute, Department of Biochemistry, University of Oxford, South 
      Parks Road, Oxford OX1 3QU, United Kingdom.
FAU - Hitchen, P G
AU  - Hitchen PG
FAU - Taylor, M E
AU  - Taylor ME
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Lectins)
RN  - 0 (Lectins, C-Type)
RN  - 0 (Mannose Receptor)
RN  - 0 (Mannose-Binding Lectins)
RN  - 0 (Monosaccharides)
RN  - 0 (Receptors, Cell Surface)
RN  - 30KYC7MIAI (Aspartic Acid)
RN  - 42HK56048U (Tyrosine)
RN  - 7006-34-0 (Asparagine)
RN  - OF5P57N2ZX (Alanine)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Alanine
MH  - Animals
MH  - Asparagine
MH  - Aspartic Acid
MH  - Binding Sites
MH  - Calcium/*metabolism
MH  - Kinetics
MH  - Lectins/genetics/*metabolism
MH  - *Lectins, C-Type
MH  - Macrophages/*metabolism
MH  - Magnetic Resonance Spectroscopy
MH  - Mannose Receptor
MH  - *Mannose-Binding Lectins
MH  - Mice
MH  - Models, Molecular
MH  - Monosaccharides/*metabolism
MH  - Mutagenesis, Site-Directed
MH  - Phenotype
MH  - Rats
MH  - Receptors, Cell Surface/genetics/*metabolism
MH  - Tyrosine
EDAT- 1997/02/28 00:00
MHDA- 1997/02/28 00:01
CRDT- 1997/02/28 00:00
PHST- 1997/02/28 00:00 [pubmed]
PHST- 1997/02/28 00:01 [medline]
PHST- 1997/02/28 00:00 [entrez]
AID - S0021-9258(18)41258-6 [pii]
AID - 10.1074/jbc.272.9.5668 [doi]
PST - ppublish
SO  - J Biol Chem. 1997 Feb 28;272(9):5668-81. doi: 10.1074/jbc.272.9.5668.