Solution conformational preferences of immunogenic peptides derived from the principal neutralizing determinant of the HIV-1 envelope glycoprotein gp120

Chandrasekhar, K; Profy, Albert T.; Dyson, H. Jane

doi:10.1021/bi00102a009

Cited by 151 publications

(138 citation statements)

References 40 publications

(44 reference statements)

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“…Since all the 5025A epitope residues are distant from both peptide coupling sites, heterogeneous coupling effects upon 5025A binding to the conjugate were probably much less significant. For 5023A, however, residue Gly 14 is a 5023A epitope residue that is adjacent to Lys 15 ; hence 5023A binding to BPTI-CRK peptide could be hindered due to surface coupling of this peptide via its Lys 15 side chain. The differences in antibody binding to the various antigens (discussed above and summarized in Table II) were all meaningful, with the possible exception of the 5023A binding to CRK-BPTI data.…”

Section: Structural Tendencies Of Uncoupled Versus Bpti-coupledmentioning

confidence: 99%

“…These methods included aminoisobutyric acid substitution (10), insertion into a viral coat protein (23), glycosylation (12)(13)(14), attachment to resin beads (24), cyclization of the peptide (15), and trifluoroethanol addition (14 -19).…”

mentioning

confidence: 99%

“…The PND peptide of interest, "RK," has the following sequence: Arg 15 . This sequence, corresponding to residues 308 -322 of the gp120 envelope protein of HIV-1 (using the gp120 numbering scheme for strain IIIB, Ref.…”

mentioning

confidence: 99%

“…Based upon the NMR and SPR data presented in this study, the relationship between peptide antigenic structure versus antibody binding preference (for this PND peptide and these antibodies) is then discussed. 15 , was synthesized and studied. The cysteine residue was required for conjugation of RK peptide to BPTI protein via a heterobifunctional chemical linker.…”

mentioning

confidence: 99%

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The Binding of a Glycoprotein 120 V3 Loop Peptide to HIV-1 Neutralizing Antibodies

Wu¹,

MacKenzie²,

Durda³

et al. 2000

Journal of Biological Chemistry

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The structural and antigenic properties of a peptide ("CRK") derived from the V3 loop of HIV-1 gp120 protein were studied using NMR and SPR techniques. The sequence of CRK corresponds to the central portion of the V3 loop containing the highly conserved "GPGR" residue sequence. Although the biological significance of this conserved sequence is unknown, the adoption of conserved secondary structure (type II ␤-turn) in this region has been proposed. The tendency of CRK (while free or conjugated to protein), to adopt such structure and the influence of such structure upon CRK antigenicity were investigated by NMR and SPR, respectively. Regardless of conjugation, CRK is conformationally averaged in solution but a weak tendency of the CRK "GPGR" residues to adopt a ␤-turn conformation was observed after conjugation. The influence of GPGR structure upon CRK antigenicity was investigated by measuring the affinities of two cognate antibodies: "5023A" and "5025A," for CRK, protein-conjugated CRK and gp120 protein. Each antibody bound to all the antigens with nearly the same affinity. From these data, it appears that: (a) antibody binding most likely involves an induced fit of the peptide and (b) the gp120 V3 loop is probably conformationally heterogeneous. Since 5023A and 5025A are HIV-1 neutralizing antibodies, neutralization in these cases appears to be independent of adopted GPGR ␤-turn structure. The principal neutralizing determinant (PND)1 of HIV-1 has been mapped to the third hypervariable (V3) loop of the HIV-1 envelope protein, gp120 (1). PND-derived peptides are used as immunogens to elicit antibodies that possess HIV-1 virus neutralization capabilities (2, 3). The binding of neutralizing antibodies blocks virus entry into the host cell but does not prevent binding of HIV-1 to its primary cell receptor protein, CD4 (4, 5). Although the V3 loop represents an important target for the development of vaccines against AIDS, its high sequence variability also makes it a very problematic one (6). Nonetheless, the occurrence of the highly conserved residue sequence, "GPGR," at the tip of the V3 loop has raised the possibility that these residues make up a conserved secondary structural element in gp120. The function of such a structural element, if one exists, is presently unknown, however. The precise predicted secondary structure adopted by the GPGR residues is a type II ␤-turn (6, 7).In order to determine whether the conserved GPGR sequence confers certain secondary structural tendencies upon this region of the V3 loop, numerous NMR studies were conducted upon a variety of V3 loop-derived peptides (8 -21). These peptides were shown to have only low density populations of folded structure and to be conformationally averaged in solution. Despite the report of a "core" gp120 protein complex crystal structure, this complex was prepared using a form of gp120 which lacked most of the hypervariable loops including V3 (22). Information regarding the actual three-dimensional structure of the V3 loop in native gp120 is theref...

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Section: Structural Tendencies Of Uncoupled Versus Bpti-coupledmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The Binding of a Glycoprotein 120 V3 Loop Peptide to HIV-1 Neutralizing Antibodies

Wu¹,

MacKenzie²,

Durda³

et al. 2000

Journal of Biological Chemistry

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“…The NMR measurements were performed at 1, 4, 14 and 29°C for the sample at pH3.0 and at 1°C and 14°C for the pH 6.5 samples. The low temperatures (and low pH) were chosen to minimize amide exchange (Wiithrich et al., 1986; Dyson et al, 1988a, b;Chandrasekhar et al, 1991). The NMR spectra of thymosin P4 at the high-salt and low-salt concentrations were almost identical.…”

mentioning

confidence: 99%

Conformation of thymosin β₄ in water determined by NMR spectroscopy

Czisch

Schleicher

Hörger

et al. 1993

European Journal of Biochemistry

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The conformational preferences of a 43-amino-acid G-actin-binding peptide, thymosin P4, in water at 1, 4 and 14°C and at pH 3.0 and 6.5 were studied by NMR. NMR showed that thymosin p4 lacks a uniquely folded conformation in water. However, some preferential a-helical conformations of thymosin /I4 can be observed in aqueous solutions. The segment at residues 5-16 showed characteristic interactions for conformations in both the P-strand and a-helical regions of the 4-y space, based on strong CH(i)-NH(i+ 1) interactions and NH-NH, C"H(i)-NH(i+3), and C"H(i)-CpH(i+3) interactions, respectively. At 1 -4"C, another segment at residues 31 -37 also shows both p and a conformations, forming however a less well-defined helix than the segment at residues 5 -16. At 14"C, the conformational population of the helix at positions 5-16 is shifted more towards the random and turn-like structures, whereas the segment at positions 31 -37 becomes exclusively a random coil.The cytoplasmic salt conditions in a non-muscle cell strongly favor the polymerization of actin and only recently has it been determined how cells manage to keep more than 50% of the actin pool in an unpolymerized state. It is now thought that thymosin P4 is the main actin-sequestering peptide, which forms a 1 : 1 complex with actin and thus shifts the polymerization equilibrium from filamentous (F-actin) to globular actin (G-actin;Weeds and Way, 1991;Safer, 1992). Furthermore, the interaction of thymosin and actin inhibits of ADP/ATP exchange in actin, consequently leading to a high concentration of ADP-actin, which has a drastically decreased tendency to form actin filaments. Profilins, another class of G-actin-binding proteins, increase the nucleotide exchange and are thought to compete with thymosin in this reaction (Goldschmidt-Clermont et al., 1992).Since the elucidation of the crystal structure of actin (Kabsch et al., 1990), it is of prime importance to determine the structures of actin-binding proteins and to characterize the nature of the protein/protein interactions. Recently, we determined the NMR structure of hisactophilin, a histidinerich actin-binding protein (Scheel et al., 1989;Habazettl et al., 1992), and of thymosin p4 (Zarbock et al., 1990). The latter, however, was obtained in solutions containing fluorinated alcohols, i.e. conditions which might not reflect the true conformation of the protein in the aqueous environment. We present in this study the determination of the solution conformation of thymosin / I 4 in water by 'H-NMR spectroscopy. Using a variety of two-dimensional (2D) NMR techniques (Emst et al., 1987), the 'H-NMR spectra were assigned in a sequential manner (Wuthrich, 1986 spectra formed the basis for the determination of the conformational preferences of thymosin p4 at different temperatures and pH. MATERIALS AND METHODS Sample preparation of thymosin p4Thymosin P4 was isolated as described by Zarbock et al. (1990). The NMR samples of thymosin P4 were dissolved in 90% H,0/10% D,O at an approximate concentration of 2 mM peptide...

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Prediction of the secondary structure of HIV-1 gp120

et al. 1996

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The secondary structure of HIV‐1 gp120 was predicted using multiple alignment and a combination of two independent methods based on neural network and nearest‐neighbor algorithms. The methods agreed on the secondary structure for 80% of the residues in BH10 gp120. Six helices were predicted in HIV strain BH10 gp120, as well as in 27 other HIV‐1 strains examined. Two helical segments were predicted in regions displaying profound sequence variation, one in a region suggested to be critical for CD4 binding. The predicted content of helix, β‐strand, and coil was consistent with estimates from Fourier transform infrared spectroscopy. The predicted secondary structure of gp120 compared well with data from NMR analysis of synthetic peptides from the V3 loop and the C4 region. As a first step towards modeling the tertiary structure of gp120, the predicted secondary structure may guide the design of future HIV sub‐unit vaccine candidates. © 1996 Wiley‐Liss, Inc.

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Solution conformational preferences of immunogenic peptides derived from the principal neutralizing determinant of the HIV-1 envelope glycoprotein gp120

Cited by 151 publications

References 40 publications

The Binding of a Glycoprotein 120 V3 Loop Peptide to HIV-1 Neutralizing Antibodies

The Binding of a Glycoprotein 120 V3 Loop Peptide to HIV-1 Neutralizing Antibodies

Conformation of thymosin β₄ in water determined by NMR spectroscopy

Prediction of the secondary structure of HIV-1 gp120

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Solution conformational preferences of immunogenic peptides derived from the principal neutralizing determinant of the HIV-1 envelope glycoprotein gp120

Cited by 151 publications

References 40 publications

The Binding of a Glycoprotein 120 V3 Loop Peptide to HIV-1 Neutralizing Antibodies

The Binding of a Glycoprotein 120 V3 Loop Peptide to HIV-1 Neutralizing Antibodies

Conformation of thymosin β4 in water determined by NMR spectroscopy

Prediction of the secondary structure of HIV-1 gp120

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Conformation of thymosin β₄ in water determined by NMR spectroscopy