PDBsum entry 2h1p

Complex (antibody/peptide)

PDB id: 2h1p

Contents

Protein chains

219 a.a. *

220 a.a. *

11 a.a. *

Waters ×62

* Residue conservation analysis

PDB id:

2h1p

Name:

Complex (antibody/peptide)

Title:

The three-dimensional structures of a polysaccharide binding antibody to cryptococcus neoformans and its complex with a peptide from a phage display library: implications for the identification of peptide mimotopes

Structure:

2h1. Chain: l. Fragment: fab. 2h1. Chain: h. Fragment: fab. Pa1. Chain: p. Engineered: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Strain: balb/c. Cell_line: 2h1 balb/c-nso hybridoma. Other_details: fab part isolated after papain digestion of the parent igg1/k molecule.

Biol. unit:

Trimer (from PQS)

Resolution:

2.40Å R-factor: 0.186

Authors:

A.C.M.Young,P.Valadon,A.Casadevall,M.D.Scharff,J.C.Sacchettini

Key ref:

A.C.Young et al. (1997). The three-dimensional structures of a polysaccharide binding antibody to Cryptococcus neoformans and its complex with a peptide from a phage display library: implications for the identification of peptide mimotopes. J Mol Biol, 274, 622-634. PubMed id: 9417940 DOI: 10.1006/jmbi.1997.1407

Date:

12-Nov-97 Release date: 28-Jan-98

Protein chain

No UniProt id for this chain

Struc: 219 a.a.

Protein chain

No UniProt id for this chain

Struc: 220 a.a.

Protein chain

No UniProt id for this chain

Struc: 11 a.a.

DOI no: 10.1006/jmbi.1997.1407

J Mol Biol 274:622-634 (1997)

PubMed id: 9417940

The three-dimensional structures of a polysaccharide binding antibody to Cryptococcus neoformans and its complex with a peptide from a phage display library: implications for the identification of peptide mimotopes.

A.C.Young, P.Valadon, A.Casadevall, M.D.Scharff, J.C.Sacchettini.

ABSTRACT

The three-dimensional structure of 2H1, a protective monoclonal antibody to Cryptococcus neoformans, has been solved at 2.4 A resolution, in both its unbound form and in complex with the 12 amino acid residue peptide PA1 (GLQYTPSWMLVG). PA1 was previously identified as a potential mimotope of the cryptococcal capsular polysaccharide by screening of a phage display peptide library. Peptide binding is associated with only minor rearrangements of some side-chains and a small shift in the H2 loop of the antibody. The peptide assumes a tightly coiled conformation consisting of one inverse gamma-turn and one type II beta-turn that serves to place the entire peptide motif, consisting of ThrP5, ProP6, TrpP8, MetP9 and LeuP10, into a depression in the antibody combining site. A small number of H-bonds between peptide and antibody contribute to the affinity and specificity. Poor steric complementarity between PA1 and the antibody heavy chain along with the fact that the majority of the interactions between 2H1 and PA1 involve van der Waals interactions with the light chain may explain why this peptide acts as only a partial mimotope of the capsular polysaccharide epitope.

Selected figure(s)

Figure 2.
Figure 2. Stereodiagram showing a superposition of the antibody binding site in the peptide-bound (open circles for C^α positions and side-chains) and the unbound forms of 2H1 (trace only, no circles). The side-chains of those residues that differ most between the peptide-bound and the unbound forms of 2H1 are marked, with designating light chain residues and H designating heavy chain residues. The Figure was produced using the program MOLSCRIPT [Kraulis 1991].

Figure 5.
Figure 5. Stereodiagram of the C^α trace of 2H1 showing H-bonding interactions between the peptide and 2H1. The peptide is shown in a ball-and-stick representation, with Ala^P2 on the left, and Gly^P12 on the right. H-bonds are represented as dotted lines. The side-chains of other residues that make van der Waals contacts with the peptide are also shown. The Figure was produced using the program MOLSCRIPT [Kraulis 1991].

The above figures are reprinted by permission from Elsevier: J Mol Biol (1997, 274, 622-634) copyright 1997.

Figures were selected by an automated process.