G14secL04Tpc3: Difference between revisions
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<Structure load='1rjl' size='350' frame='true' align='right' caption= 'OspB bound to H6831' scene= 'G14secL04Tpc3/Ospb_in_complex/2'/> | <Structure load='1rjl' size='350' frame='true' align='right' caption= 'OspB bound to H6831' scene= 'G14secL04Tpc3/Ospb_in_complex/2'/> | ||
<scene name='G14secL04Tpc3/Antibody_showing2/1'>Antibody Fab fragment H6831 </scene> (<scene name='G14secL04Tpc3/Heavy_chain/1'>Heavy chain</scene> and <scene name='G14secL04Tpc3/Light_chain/1'>light chain</scene>)has been shown to bind on an epitope of the <scene name='G14secL04Tpc3/Ospb_in_complex_with_heavy_and/2'>OspB protein</scene>. Once this occurs, the resulting OspB∙H6831 complex is formed and the first four beta strands of the OspB protein are proteolysed | <scene name='G14secL04Tpc3/Antibody_showing2/1'>Antibody Fab fragment H6831 </scene> (<scene name='G14secL04Tpc3/Heavy_chain/1'>Heavy chain</scene> and <scene name='G14secL04Tpc3/Light_chain/1'>light chain</scene>)has been shown to bind on an epitope of the <scene name='G14secL04Tpc3/Ospb_in_complex_with_heavy_and/2'>OspB protein</scene><ref name ="1rjl_pdb" />. Once this occurs, the resulting OspB∙H6831 complex is formed and the first four beta strands of the OspB protein are proteolysed<ref name ="1rjl_pdb" />. Cleavage of these first four beta strands somehow causes bacterial lysis of the ''B. burdgorferi''. This loss is the most significant conformational change in the OspB protein itself, and all other changes are minor and appear to be related to this loss. The majority of the binding occurs on the C-terminus of OspB. The C-terminus consists of <scene name='G14secL04Tpc3/Three_major_loops2/3'>three major loops </scene> | ||
that are involved in the electrostatic forces keeping the H6831 antibody bound to the OspB protein. Of these three loops, <scene name='G14secL04Tpc3/Loop_2/4'>loop 2</scene> | that are involved in the electrostatic forces keeping the H6831 antibody bound to the OspB protein<ref name ="1rjl_pdb" />. Of these three loops, <scene name='G14secL04Tpc3/Loop_2/4'>loop 2</scene> | ||
plays the most significant role in keeping the complex together. This is due to the presence of a <scene name='G14secL04Tpc3/Lysine-253/3'>lysine at residue 253</scene> | plays the most significant role in keeping the complex together. This is due to the presence of a <scene name='G14secL04Tpc3/Lysine-253/3'>lysine at residue 253</scene> | ||
on this loop. This important lysine forms an ionic salt bridge with the <scene name='G14secL04Tpc3/Lysine-253_and_glu50/2'>glutamic acid at residue 50</scene> | on this loop. This important lysine forms an ionic salt bridge with the <scene name='G14secL04Tpc3/Lysine-253_and_glu50/2'>glutamic acid at residue 50</scene> | ||
on the heavy chain of the antibody Fab Fragment. Thus, formation of the complex consist of the C-terminus of the OspB protein coming into contact with the variable regions of the H6831 antibody Fab fragment and the lysine-253 wedging between the two <scene name='G14secL04Tpc3/Lysine-253_glu50_tyr_and_trp/2'>aromatic residues</scene> | on the heavy chain of the antibody Fab Fragment. Thus, formation of the complex consist of the C-terminus of the OspB protein coming into contact with the variable regions of the H6831 antibody Fab fragment and the lysine-253 wedging between the two <scene name='G14secL04Tpc3/Lysine-253_glu50_tyr_and_trp/2'>aromatic residues</scene> | ||
(tryptophan-33 and tyrosine-101) and salt bridging with the glu-50 on the heavy chain of the antibody. Studies show that other bacterial strains having a cysteine, glycine, glutamic acid, or threonine in place of Lys-253 demonstrate resistance to the bactericidal effects of H6831 and also less binding affinity for the antibody Fab fragment (citation needed). This bolsters how important the Lys-253 is in the binding between the OspB protein and the antibody. After the complex is formed and the first four beta strands are cleaved off, a relic of this loss is a single <scene name='G14secL04Tpc3/Freely_floating_beta_strand/2'>freely floating beta strand</scene> on the N-terminus of the protein. This beta strand plays a role in the formation of dimers of OspB∙H6831 complex(citation). Although the second loop bearing the lysine is very important, the other loops certainly contribute to the bonding between OspB and the antibody fab fragment. For example, a <scene name='G14secL04Tpc3/Threonine_and_light_chain/1'>threonine</scene> | (tryptophan-33 and tyrosine-101) and salt bridging with the glu-50 on the heavy chain of the antibody<ref name ="1rjl_pdb" />. Studies show that other bacterial strains having a cysteine, glycine, glutamic acid, or threonine in place of Lys-253 demonstrate resistance to the bactericidal effects of H6831 and also less binding affinity for the antibody Fab fragment (citation needed). This bolsters how important the Lys-253 is in the binding between the OspB protein and the antibody. After the complex is formed and the first four beta strands are cleaved off, a relic of this loss is a single <scene name='G14secL04Tpc3/Freely_floating_beta_strand/2'>freely floating beta strand</scene> on the N-terminus of the protein. This beta strand plays a role in the formation of dimers of OspB∙H6831 complex(citation). Although the second loop bearing the lysine is very important, the other loops certainly contribute to the bonding between OspB and the antibody fab fragment. For example, a <scene name='G14secL04Tpc3/Threonine_and_light_chain/1'>threonine</scene> | ||
at residue 276 on another loop interacts with residues on the light chain of the antibody fragment. | at residue 276 on another loop interacts with residues on the light chain of the antibody fragment. | ||
==References== | ==References== | ||
<references /> | <references /> | ||
