Detection of cross-links in insect cuticle by REDOR NMR spectroscopy

Christensen, Allyson M.; Schaefer, Jacob; Kramer, Karl J.; Morgan, Thomas D.; Hopkins, Theodore L.

doi:10.1021/ja00018a013

Cited by 59 publications

(38 citation statements)

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“…Covalent links between imidazole nitrogen and ring carbon in dopamine derivatives (Schaefer et al, 1987) as well as between imidazole nitrogen and the /}-carbon atom (Christensen et al, 1991) have been demonstrated in sclerotized Manduca sexta pupal cuticle by means of solid state NMR spectroscopy. The adducts produced in vitro between NAH and NADA appear thus to represent structures actually present in sclerotized cuticle.…”

Section: Discussionmentioning

confidence: 99%

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Cuticle-catalyzed coupling between N-acetylhistidine and N-acetyldopamine

Andersen

Peter

Roepstorff³

1992

Insect Biochemistry and Molecular Biology

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Cuticle-catalyzed coupling between N-acetylhistidine and N-acetyldopamine U n i v e r s i t ä t P o t s d a mPostprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe ; 72 fi rst published in: Insect Biochemistry and Molecular Biology. -22 (1992) Abstract-Several types of insect cuticle contain enzymes catalyzing the formation of adducts between JV-acetyldopamine (NADA) and 7V-acetylhistidine (NAH). Two such adducts, NAH-NADA-I and NAH NADA-II, have been isolated and their stuctures determined. In one of the adducts the link connecting the two residues occurs between the 1-position (/!-position) in the NADA side chain and the 1-N atom (T-N) in the imidazole ring of histidine. Diphenoloxidase activity alone is not sufficient for formation of this adduct, whereas extracts containing both diphenoloxidase and o-quinone-p-quinone methide isomerase activities catalyze the coupling reaction. The adduct consists of a mixture of two diastereomers and they are presumably formed by spontaneous reaction between enzymatically produced NADA-p-quinone methide and JV-acetylhistidine.The other adduct has been identified as a ring addition product of JV-acetylhistidine and NADA. In contrast to the former adduct it can be formed by incubation of the two substrates with mushroom tyrosinase alone.An adduct between JV-acetylhistidine and the benzodioxan-type NADA-dimer is produced in vitro, when the TV-acetylhistidine-NADA adduct is incubated with NADA and locust cuticle containing a 1,2-dehydro-NADA generating enzyme system.Trimeric NADA-polymerization products of the substituted benzodioxan-type have been obtained from in vivo sclerotized locust cuticle, confirming the ability of cuticle to produce NADA-oligomers.The results indicate that some insect cuticles contain enzymes promoting linkage of oxidized NADA to histidine residues. It is suggested that histidine residues in the cuticular proteins can serve as acceptors for oxidized NADA and that further addition of NADA-residues to the phenolic groups of bound NADA can occur, resulting in formation of protein-linked NADA-oligomers. The coupling reactions identified may be an important step in natural cuticular sclerotization.

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Section: Discussionmentioning

confidence: 99%

“…By means of REDOR NMR spectroscopy the presence of bonds between imidazole nitrogen in histidine residues and the beta carbon atom in the side chain of dopamine derivatives has recently been demonstrated (Christensen et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

Cuticle-catalyzed coupling between N-acetylhistidine and N-acetyldopamine

Andersen

Peter

Roepstorff³

1992

Insect Biochemistry and Molecular Biology

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“…Although there is not yet anything known about the function or developmental expression pattern of these proteins, it is tempting to speculate that some of them represent extracellular structural proteins, such as many proline-or hydroxyproline-rich glycoproteins in plant cell walls (15,16) or histidine-rich proteins in Hydra nematocysts (17). Cross-linking of EmGAM56-and EmGAM82-derived peptides via dopamine has been shown in the oocyst wall (3), and His-rich proteins such as EtGAM22 might also be involved in stabilizing extracellular structures via cross-links between His and catechols, as described for insect cuticles (8,14,43).…”

Section: Discussionmentioning

confidence: 99%

Excystation of Eimeria tenella Sporozoites Impaired by Antibody Recognizing Gametocyte/Oocyst Antigens GAM22 and GAM56

et al. 2008

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Eimeria tenella is the causative agent of coccidiosis in poultry. Infection of the chicken intestine begins with ingestion of sporulated oocysts releasing sporocysts, which in turn release invasive sporozoites. The monoclonal antibody E2E5 recognizes wall-forming body type II (WFBII) in gametocytes and the WFBII-derived inner wall of oocysts. Here we describe that this antibody also binds to the stieda body of sporocysts and significantly impairs in vitro excystation of sporozoites. Using affinity chromatography and protein sequence analysis, E2E5 is shown to recognize EtGAM56, the E. tenella ortholog of the Eimeria maxima gametocyte-specific GAM56 protein. In addition, this antibody was used to screen a genomic phage display library presenting E. tenella antigens as fusion proteins with the gene VIII product on the surfaces of phagemid particles and identified the novel 22-kDa histidine-and proline-rich protein EtGAM22. The Etgam22 mRNA is expressed predominantly at the gametocyte stage, as detected by Northern blotting. Southern blot analysis in combination with data from the E. tenella genome project revealed that Etgam22 is an intronless multicopy gene, with approximately 12 to 22 copies in head-to-tail arrangement. Conspicuously, Etgam56 is also intronless and is localized adjacent to another gam56-like gene, Etgam59. Our data suggest that amplification is common for genes encoding oocyst wall proteins.Coccidiosis in poultry is caused by protozoan parasites of the genus Eimeria. Worldwide economic losses due to these parasites have been estimated to exceed 1.2 billion U.S. dollars per annum (41). The most virulent species is Eimeria tenella, causing severe hemorrhagic enteritis by infection of the epithelium and submucosa of the ceca and, eventually, death of infected chickens (24).Eimeria infections occur by ingestion of oocysts (24). In the intestine, oocysts release four sporocysts, each containing two sporozoites. After excystation, motile infective sporozoites actively enter cells in the epithelium of the cecum. Three rounds of asexual multiplication in the epithelium and submucosa are then followed by differentiation to sexual stages of micro-and macrogametocytes (23). After fertilization of macrogametes, a complex, two-layered wall is secreted around the young oocyst by exocytosis of wall-forming body type I and type II (WFBI and WFBII) (35). While the 10-nm-thick outer oocyst wall is built up by the contents of WFBI, the 90-nm inner oocyst wall is composed mainly of glycoproteins that were stored in WFBII (31, 37). The oocyst displays a remarkable rigidity and protects the parasite from several physically and chemically adverse influences, such as commonly used disinfectants (34). A potential use of gametocyte antigens involved in formation of the oocyst wall as protective transmission-blocking vaccines has been described for Eimeria maxima (2,4,25,(38)(39)(40)46).The formation of oocyst and sporocyst walls and sporozoite excystation are rather complex processes that we are just beginning to underst...

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“…It is notable for another reason, namely that its gene is present in extremely high copy number (in contrast to the single copies of the genes for, for example, EmGam56 and EmGam82), indicating that it may be important in oocyst wall formation via a mechanism distinct from that of the tyrosine-rich proteins. As yet, no information is available about whether this 22 kDa protein is processed into smaller polypeptides nor how it is incorporated into the oocyst wall, though its involvement in stabilizing the oocyst wall via cross-links between histidine and catechols, as seen in insect cuticles (Christensen et al 1991, Xu et al 1997, Kerwin et al 1999, is a distinct possibility (Krücken et al 2008). …”

Section: Proteins Of the Oocyst Wallmentioning

confidence: 99%