JKMRS Volume 20, No 3, pp 95; Solution State Structure of P1, ... | |
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2016년 09월 20일 / 조회수: 662 | |
Solution State Structure of P1, the Mimetic
Peptide Derived from IgM Antigen Apo
B-100 by NMR
Gilhoon Kim, Hyuk Lee, Hyewon Oh and Hoshik Won*
Department of Applied Chemistry, Hanyang University,
55, Hanyang Daehak-Ro, Sangrok-Gu, Ansan 426-791, Republic of Korea
Received Aug 2, 2016; Revised
Aug 15, 2016; Accepted Aug 23, 2016 Abstract Apolipoprotein
B-100 (Apo-B100) is a major component of low density lipoprotein (LDL). Apo
B-100 protein has 4,536 amino acid sequence and these amino acids are classified
into peptide groups A to G with subsequent 20 amino acids (P1-P302). The
peptide groups were act as immunoglobulin (Ig) antigens which oxidized via
malondialdehyde (MDA). The mimetic peptide P1 (EEEMLENVSLVCPKDAT RFK) out of
D-group peptides carrying the highest value of IgG antigens were selected for
structural studies that may provide antigen specificity. Circular Dichroism (CD)
spectra were measured for peptide secondary structure in the range of 190-250
nm. Experimental results show that P1 exhibit partial of β-sheet and random
coil structure. Homonuclear (COSY, TOCSY, NOESY) 2D- NMR experiments were
carried out for NMR signal assignments and structure determination for P1. On
the basis of these completely assigned NMR spectra and distance data, distance
geometry (DG) and Molecular dynamics (MD) were carried out to determine the
structures of P1. The proposed structure was selected by comparisons between experimental
NOE spectra and back calculated 2D NOE results from determined structure showing
acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P1 obtained
upon superposition of all atoms was in the range 0.33Å. The solution state P1
has mixed structure of β-sheet (Glu[1] to Cys[12]) and random coil (Pro[13] to
Lys[20]). These NMR results are well consistent with secondary structure from experimental
results of circular dichroism. Structural studies based on NMR may contribute
to the studies of atherosclerosis and observed conformational characteristics of
apo B-100 in LDL using monoclonal antibodies.
Keywords Apolipoprotein B-100,
Immunoglobulin, Molecular dynamic computation, NMR
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