2gki
From Proteopedia
(New page: 200px<br /> <applet load="2gki" size="450" color="white" frame="true" align="right" spinBox="true" caption="2gki, resolution 2.88Å" /> '''Heavy and light cha...) |
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| - | [[Image:2gki.gif|left|200px]]<br /> | + | [[Image:2gki.gif|left|200px]]<br /><applet load="2gki" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="2gki" size=" | + | |
caption="2gki, resolution 2.88Å" /> | caption="2gki, resolution 2.88Å" /> | ||
'''Heavy and light chain variable single domains of an anti-DNA binding antibody hydrolyze both double- and single-stranded DNAs without sequence specificity'''<br /> | '''Heavy and light chain variable single domains of an anti-DNA binding antibody hydrolyze both double- and single-stranded DNAs without sequence specificity'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Anti-DNA antibodies (Abs) are of biomedical interest because they are | + | Anti-DNA antibodies (Abs) are of biomedical interest because they are associated with autoimmune diseases in human and mice. Previously we isolated an anti-DNA monoclonal Ab 3D8 from an autoimmune-prone MRL-lpr/lpr mouse. Here we have characterized DNA binding kinetics and hydrolyzing activities of the recombinant single chain variable fragment (scFv) and the single variable domains of heavy chain (VH) and light chain (VL) using various single-stranded (ss) and double-stranded (ds) DNA substrates. All the Abs bound to both ds- and ssDNAs without significant preferential sequence specificity showing scFv higher affinities (KD = approximately 17-74 nm) than VH (KD = approximately 2.4-8.4 microm) and VL (KD = approximately 3.2-72 microm), and efficiently hydrolyzed both ds- and ssDNAs without sequence specificity in a Mg2+-dependent manner, except for the poor activity of 3D8 scFv for ss-(dT)40. Elucidated crystal structure-based His to Ala mutations on the complementarity determining regions of VH (His-H35 --> Ala) and/or VL (His-L94 --> Ala) of 3D8 scFv significantly inhibited the catalytic activities, indicating that the His residues are involved in the catalytic mechanism of 3D8 scFv. However, the DNA hydrolyzing activities of single domain VH and VL were not affected by the mutations, indicative of their different catalytic mechanisms from that of 3D8 scFv. Our results demonstrate single domain Abs with DNase activities for the first time, which might provide new insights into substrate recognition and catalytic mechanisms of anti-DNA Abs. |
==About this Structure== | ==About this Structure== | ||
| - | 2GKI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http:// | + | 2GKI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GKI OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 13: | ||
[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chung, Y | + | [[Category: Chung, Y C.]] |
| - | [[Category: Kim, J | + | [[Category: Kim, J S.]] |
| - | [[Category: Kim, Y | + | [[Category: Kim, Y R.]] |
| - | [[Category: Kim, Y | + | [[Category: Kim, Y S.]] |
| - | [[Category: Kwon, M | + | [[Category: Kwon, M H.]] |
| - | [[Category: Lee, S | + | [[Category: Lee, S C.]] |
| - | [[Category: Lee, S | + | [[Category: Lee, S H.]] |
| - | [[Category: Lee, W | + | [[Category: Lee, W R.]] |
| - | [[Category: Shim, H | + | [[Category: Shim, H K.]] |
| - | [[Category: Sohn, J | + | [[Category: Sohn, J N.]] |
[[Category: anti-dna antibody]] | [[Category: anti-dna antibody]] | ||
[[Category: catalytic antibody]] | [[Category: catalytic antibody]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:32:34 2008'' |
Revision as of 15:32, 21 February 2008
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Heavy and light chain variable single domains of an anti-DNA binding antibody hydrolyze both double- and single-stranded DNAs without sequence specificity
Overview
Anti-DNA antibodies (Abs) are of biomedical interest because they are associated with autoimmune diseases in human and mice. Previously we isolated an anti-DNA monoclonal Ab 3D8 from an autoimmune-prone MRL-lpr/lpr mouse. Here we have characterized DNA binding kinetics and hydrolyzing activities of the recombinant single chain variable fragment (scFv) and the single variable domains of heavy chain (VH) and light chain (VL) using various single-stranded (ss) and double-stranded (ds) DNA substrates. All the Abs bound to both ds- and ssDNAs without significant preferential sequence specificity showing scFv higher affinities (KD = approximately 17-74 nm) than VH (KD = approximately 2.4-8.4 microm) and VL (KD = approximately 3.2-72 microm), and efficiently hydrolyzed both ds- and ssDNAs without sequence specificity in a Mg2+-dependent manner, except for the poor activity of 3D8 scFv for ss-(dT)40. Elucidated crystal structure-based His to Ala mutations on the complementarity determining regions of VH (His-H35 --> Ala) and/or VL (His-L94 --> Ala) of 3D8 scFv significantly inhibited the catalytic activities, indicating that the His residues are involved in the catalytic mechanism of 3D8 scFv. However, the DNA hydrolyzing activities of single domain VH and VL were not affected by the mutations, indicative of their different catalytic mechanisms from that of 3D8 scFv. Our results demonstrate single domain Abs with DNase activities for the first time, which might provide new insights into substrate recognition and catalytic mechanisms of anti-DNA Abs.
About this Structure
2GKI is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
Heavy and light chain variable single domains of an anti-DNA binding antibody hydrolyze both double- and single-stranded DNAs without sequence specificity., Kim YR, Kim JS, Lee SH, Lee WR, Sohn JN, Chung YC, Shim HK, Lee SC, Kwon MH, Kim YS, J Biol Chem. 2006 Jun 2;281(22):15287-95. Epub 2006 Mar 20. PMID:16551636
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