1H NMR Study of the Solution Structure of Ac-AMP2, a Sugar Binding Antimicrobial Protein Isolated fromAmaranthus caudatus

Martins, José; Maes, Dominique; Loris, Remy; Pepermans, Henri; Wyns, Lode; Willem, Rudolph; Verheyden, Patricia

doi:10.1006/jmbi.1996.0253

Cited by 87 publications

(62 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Many chitin-binding lectins have a structural motif called the "hevein domain" (28), which is comprised of 40 -45 residues and has a conserved cystine-disulfide core (27). The smallest of these, Ac-AMP2 from Amaranthus caudatus, has 30 residues including six cysteines.…”

Section: Discussionmentioning

confidence: 99%

Retrocyclin, an Antiretroviral θ-Defensin, Is a Lectin

Wang¹,

Cole²,

Hong³

et al. 2003

The Journal of Immunology

184

164

View full text Add to dashboard Cite

θ-Defensins are circular octadecapeptides that contain an internal tridisulfide ladder. Because retrocyclin-1, an ancestral hominid θ-defensin, can protect human cells in vitro from infection by T- and M-tropic strains of HIV-1, we used surface plasmon resonance techniques to study its binding to glycoproteins and glycolipids implicated in HIV-1 entry. Retrocyclin-1 bound with high affinity to gp120 (Kd, 35.4 nM), CD4 (Kd, 31 nM), and galactosylceramide (Kd, 24.1 nM). Neither a circular form of retrocyclin without its tridisulfide ladder nor its β-hairpin precursor with these disulfides intact bound gp120 or CD4 effectively. Retrocyclin also bound fetuin, an extensively glycosylated protein, with high affinity, but it did not bind nonglycosylated gp120 or BSA. However, retrocyclin did bind to a neoglycoprotein, BSA, with covalently attached sugar residues. Experiments with glycosidase-treated fetuin, gp120, and CD4 revealed that both O-linked and N-linked sugars were used as binding sites. In a panel of retrocyclin variants, binding to immobilized gp120 and CD4 were highly correlated to each other and to the peptide’s ability to protect human PBMCs from infection by HIV-1. Although small, cysteine-rich antimicrobial peptides with lectin-like properties exist in plants, θ-defensins are the first such molecules to be identified in vertebrates. Retrocyclin’s ability to recognize and bind carbohydrate-containing surface molecules is integrally related to its ability to protect cells from HIV-1 infection.

show abstract

Section: Discussionmentioning

confidence: 99%

Retrocyclin, an Antiretroviral θ-Defensin, Is a Lectin

Wang¹,

Cole²,

Hong³

et al. 2003

The Journal of Immunology

184

164

View full text Add to dashboard Cite

show abstract

“…chitinase (Ch-chit) (28), 44-kDa glycoprotein from Lucilia cuprina (Peritrophin-44) (13), and Trichoplusia ni intestinal mucin (Tn-IM) (29). Plants are as follows: hevein from rubber tree (Hevein) (9), Amaranthus caudatus antimicrobial protein 2 (Ac-AMP2) (10), and four homologous domains of wheat germ agglutinin (WGA A, -B, -C, and -D) (11). Residue numbers for each segment are indicated in parentheses.…”

Section: Nmr Structure Of the Invertebrate Chitin-binding Protein 179mentioning

confidence: 99%

Chitin-binding Proteins in Invertebrates and Plants Comprise a Common Chitin-binding Structural Motif

Suetake

Tsuda

Kawabata

et al. 2000

Journal of Biological Chemistry

135

114

View full text Add to dashboard Cite

Tachycitin, a 73-residue polypeptide having antimicrobial activity is present in the hemocyte of horseshoe crab (Tachypleus tridentatus). The first three-dimensional structure of invertebrate chitin-binding protein was determined for tachycitin using two-dimensional nuclear magnetic resonance spectroscopy. The measurements indicate that the structure of tachycitin is largely divided into N-and C-terminal domains; the former comprises a three-stranded ␤-sheet and the latter a two-stranded ␤-sheet following a short helical turn. The latter structural motif shares a significant tertiary structural similarity with the chitin-binding domain of plant chitin-binding protein. This result is thought to provide faithful experimental evidence to the recent hypothesis that chitin-binding proteins of invertebrates and plants are correlated by a convergent evolution process.An invertebrate chitin-binding protein named tachycitin is recently found to be a member of the primordial elements of innate immune defense against bacterial and fungal infections (1-5). The antimicrobial activity is initially identified for chitin-binding proteins extracted from plants (6 -7), which commonly comprise single or multiple copies of the chitin-binding domain. The plant chitin-binding domain is mostly composed of 30 -43 residues including eight cysteines, three aromatic residues, and glycines and is frequently referred to as a hevein domain (8). It has been well demonstrated that this domain is indispensable for the antimicrobial activity and exhibits a significant conservation in primary sequence (Ͼ40%) and in three-dimensional (3D) 1 structure (9 -12). Although this advanced knowledge has been provided for the plant chitin-binding proteins, less is known for the invertebrate chitin-binding proteins including tachycitin (1,(13)(14)(15)(16). Kawabata et al. (1) identified that tachycitin is a 73-residues chitin-binding protein having antimicrobial activity. They also revealed that tachycitin consists of five intramolecular disulfide bridges; the connected Cys pairs are 6 -33, 12-30, 24 -61, 25-68, and 40 -53. For invertebrates, the chitin-binding domain was assumed to comprise about 65 residues (17) involving a high percentage of cysteine and aromatic residues in a similar manner to the plant chitin-binding domain. On the basis of such similarity between plant and invertebrate chitin-binding proteins, Shen and Jacobs-Lorena (17) proposed a hypothesis that they are correlated by a rare evolutional process, convergent evolution, i.e. proteins from different origins develop to construct the same active site structure to acquire the same function. However, complete lack of 3D-structural information of invertebrate chitin-binding protein obscures the evolutional relationship between invertebrate and plant chitin-binding proteins. The present study determines the solution structure of tachycitin using NMR spectroscopy, which provides the first 3D structural information of invertebrate chitin-binding protein. EXPERIMENTAL PROCEDURESAn invertebrate...

show abstract

“…Among them, the hevein-like peptides, such as hevein from laticifers of rubber tree (4,5), antimicrobial peptides from Amaranthus caudatus seeds (Ac-AMP) (6,7), and antifungal peptides from the seeds of Pharbitis nil (Pn-AMP) (8), have specific chitin-binding activities and are characterized by three or four disulfides to stabilize a chitin-binding domain referred as hevein domain (2,9) as shown in Figure 1. This hevein domain mostly consists of 30-43 residues including six or eight cysteines pairing into three or four disulfide bonds, three aromatic residues, two glycines, and one serine ( Figure 1) and occurs in a variety of plant proteins and peptides in multiple or single copies, respectively (2).…”

mentioning

confidence: 99%

Solution Structure of Eucommia Antifungal Peptide: A Novel Structural Model Distinct with a Five-Disulfide Motif^,

Huang

Xiang

et al. 2004

Biochemistry

View full text Add to dashboard Cite

The three-dimensional structure in aqueous solution of Eucommia antifungal peptide 2 (EAFP2) from Eucommia ulmoides Oliv was determined using 1 H NMR spectroscopy. EAFP2 is a newly discovered 41-residue peptide distinct with a five-disulfide cross-linked motif. This peptide exhibits chitin-binding activity and inhibitory effects on the growth of cell wall chitin-containing fungi and chitin-free fungi. The structure was calculated by using torsion angle dynamic simulated annealing with a total of 614 distance restraints and 16 dihedral restraints derived from NOESY and DQF-COSY spectra, respectively. The five disulfide bonds were assigned from preliminary structures using a statistical analysis of intercystinyl distances. The solution structure of EAFP2 is presented as an ensemble of 20 conformers with a backbone RMS deviation of 0.65 ((0.13) Å for the well-defined Cys3-Cys39 segment. The tertiary structure of EAFP2 represents the first five-disulfide cross-linked structural model of the plant antifungal peptide. EAFP2 adopts a compact global fold composed of a 3 10 helix (Cys3-Arg6), an R-helix (Gly26-Cys30), and a three-strand antiparallel -sheet (Cys16-Ser18, Tyr22-Gly24, and Arg36-Cys37). The tertiary structure of EAFP2 shows a chitin-binding domain (residues 11-30) with a hydrophobic face and a characteristic sector formed by the N-terminal 10 residues and the C-terminal segment cross-linked through the unique disulfide bond Cys7-Cys37, which brings all four positively charged residues (Arg6, Arg9, Arg36, and Arg40) onto a cationic face. On the basis of such a structural feature, the possible structural basis for the functional properties of EAFP2 is discussed.

show abstract

1H NMR Study of the Solution Structure of Ac-AMP2, a Sugar Binding Antimicrobial Protein Isolated fromAmaranthus caudatus

Cited by 87 publications

References 0 publications

Retrocyclin, an Antiretroviral θ-Defensin, Is a Lectin

Retrocyclin, an Antiretroviral θ-Defensin, Is a Lectin

Chitin-binding Proteins in Invertebrates and Plants Comprise a Common Chitin-binding Structural Motif

Solution Structure of Eucommia Antifungal Peptide: A Novel Structural Model Distinct with a Five-Disulfide Motif^,

Contact Info

Product

Resources

About

1H NMR Study of the Solution Structure of Ac-AMP2, a Sugar Binding Antimicrobial Protein Isolated fromAmaranthus caudatus

Cited by 87 publications

References 0 publications

Retrocyclin, an Antiretroviral θ-Defensin, Is a Lectin

Retrocyclin, an Antiretroviral θ-Defensin, Is a Lectin

Chitin-binding Proteins in Invertebrates and Plants Comprise a Common Chitin-binding Structural Motif

Solution Structure of Eucommia Antifungal Peptide: A Novel Structural Model Distinct with a Five-Disulfide Motif,

Contact Info

Product

Resources

About

Solution Structure of Eucommia Antifungal Peptide: A Novel Structural Model Distinct with a Five-Disulfide Motif^,