Characterization of the fatty acyl elongation reactions involved in hydrocarbon biosynthesis in the housefly, Musca domestica L.

1988 ◽  
Vol 18 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Apollo H. Vaz ◽  
Gary J. Blomquist ◽  
Ronald C. Reitz
1989 ◽  
Vol 92 (2) ◽  
pp. 163-171
Author(s):  
J.B. Ulmer ◽  
E.D. Dolci ◽  
G.E. Palade

We have identified mature and putative precursor forms of glycophorins expressed in a virus-transformed murine erythroleukaemia (MEL) cell line and compared them with their normal erythroblast counterparts. The following differences were found: (1) the two major MEL cell glycophorins (apparent Mr values 29–30 and 43(x10(3] have greater mobility on polyacrylamide gels than their normal gp-3 and gp-2 counterparts, due at least in part to differences in their oligosaccharide sidechains; (2) MEL cell gp-3 consists of two discrete proteins; and (3) there are more potential glycophorin precursors in MEL cells than in normal mouse erythroblasts. Four proteins, with apparent Mr values of 21, 23, 26 and 27(x10(3], have tentatively been identified as glycophorin precursors, based on the following findings: (1) they are immunologically related to the glycophorins; and (2) their synthesis was induced by dimethyl sulphoxide coincidentally with that of gp-3 and gp-2. They do not appear to be glycoproteins, as evidenced by their lack of incorporation of [3H]galactose, [3H]glucosamine or [3H]mannose. In contrast, gp-3 and gp-2 incorporated [3H]galactose and [3H]glucosamine but not [3H]mannose. Partial characterization of the glycan moieties of MEL cell glycophorins indicates that they consist mostly of tri- and tetrasaccharides, with no indication of any N-linked chains. Hence, the glycans of MEL cell glycophorins are mostly (if not all) O-linked. Furthermore, treatment with N-glycanase did not change their electrophoretic mobility on polyacrylamide gels. MEL cell glycophorins were also shown to be modified by phosphoryl and fatty acyl groups.


2022 ◽  
Vol 119 (3) ◽  
pp. e2113120119
Author(s):  
Florian Hubrich ◽  
Nina M. Bösch ◽  
Clara Chepkirui ◽  
Brandon I. Morinaka ◽  
Michael Rust ◽  
...  

Lipopeptides represent a large group of microbial natural products that include important antibacterial and antifungal drugs and some of the most-powerful known biosurfactants. The vast majority of lipopeptides comprise cyclic peptide backbones N-terminally equipped with various fatty acyl moieties. The known compounds of this type are biosynthesized by nonribosomal peptide synthetases, giant enzyme complexes that assemble their products in a non–gene-encoded manner. Here, we report the genome-guided discovery of ribosomally derived, fatty-acylated lipopeptides, termed selidamides. Heterologous reconstitution of three pathways, two from cyanobacteria and one from an arctic, ocean-derived alphaproteobacterium, allowed structural characterization of the probable natural products and suggest that selidamides are widespread over various bacterial phyla. The identified representatives feature cyclic peptide moieties and fatty acyl units attached to (hydroxy)ornithine or lysine side chains by maturases of the GCN5-related N-acetyltransferase superfamily. In contrast to nonribosomal lipopeptides that are usually produced as congener mixtures, the three selidamides are selectively fatty acylated with C10, C12, or C16 fatty acids, respectively. These results highlight the ability of ribosomal pathways to emulate products with diverse, nonribosomal-like features and add to the biocatalytic toolbox for peptide drug improvement and targeted discovery.


2003 ◽  
Vol 37 (6) ◽  
pp. 722-728 ◽  
Author(s):  
Valeria Alejandra Labud ◽  
Liliana Graciela Semenas ◽  
Francisca Laos

OBJECTIVE: Odorous compounds produced at the biosolids composting plant in Bariloche (NW Patagonia) attract a variety of insects, mainly belonging to the order Diptera. In order to characterize these flies, collected specimens were taxonomically identified, their community characteristics were described and their sanitary and synanthropic importance and autochthonous or introduced character were determined. METHODS: Sampling was performed from October 1999 until March 2000. Adults were collected using an entomological net, and larvae and puparia were obtained from the composting material and incubated to obtain adults. Richness, abundance and sex ratio were calculated. RESULTS: A total of 9 taxa of Diptera were identified: Sarconesia chlorogaster, Phaenicia sericata, Calliphora vicina, Cochliomya macellaria, Ophyra sp, Muscina stabulans, Musca domestica, Sarcophaga sp and Fannia sp. Specimens of Anthomyiidae, Acaliptratae and one larva of Eristalis tenax were also found. Ophyra sp. was the most abundant taxa. All the captured Diptera belonged to introduced taxa. Most of them are considered to be eusynanthropic and/or hemisynanthropic and have sanitary importance as they may cause myiasis and pseudomyiasis. The high number of females registered and the finding of immature stages indicated that flies can develop their complete life cycle on biosolid composting windrows. CONCLUSIONS: The characterization of flies obtained in this study may be useful for defining locations of urban or semi-urban composting facilities. It also highlights the importance of sanitary precautions at such plants.


1987 ◽  
Vol 65 (5) ◽  
pp. 1158-1166 ◽  
Author(s):  
F. Michael Barrett

A tyrosinase, enzyme A, and a laccase, enzyme B, have been partially purified from larval cuticle of the flesh fly Sarcophaga bullata. Enzyme A (EC 1.10.3.1, o-diphenol: O2 oxidoreductase) oxidizes o-diphenols but not p-diphenols, is strongly inhibited by phenylthiourea, and has a pH optimum around pH 6.5–7.0. Assays on intact cuticle suggest that it becomes maximally activated at pH between 8 and 9. Enzyme B (EC 1.10.3.2, p-diphenol: O2 oxidoreductase) oxidizes both o-diphenols and p-diphenols, is not inhibited by phenylthiourea but is inhibited by concentrations of sodium azide that have little effect on enzyme A, and has a pH optimum near pH 4.5. Enzyme A was identified in extracts of cuticle from nine other species representing five orders. Enzyme B was much less readily extractable but was partially purified from larval cuticle of Phormia regina, Musca domestica, and Lucilia sericata. A summary of all species studied to date makes possible the test of a hypothesis about the distribution of these cuticular phenoloxidases within the Insecta.


2017 ◽  
Vol 199 (9) ◽  
Author(s):  
James K. Christenson ◽  
Matthew R. Jensen ◽  
Brandon R. Goblirsch ◽  
Fatuma Mohamed ◽  
Wei Zhang ◽  
...  

ABSTRACT Bacteria from different phyla produce long-chain olefinic hydrocarbons derived from an OleA-catalyzed Claisen condensation of two fatty acyl coenzyme A (acyl-CoA) substrates, followed by reduction and oxygen elimination reactions catalyzed by the proteins OleB, OleC, and OleD. In this report, OleA, OleB, OleC, and OleD were individually purified as soluble proteins, and all were found to be essential for reconstituting hydrocarbon biosynthesis. Recombinant coexpression of tagged OleABCD proteins from Xanthomonas campestris in Escherichia coli and purification over His6 and FLAG columns resulted in OleA separating, while OleBCD purified together, irrespective of which of the four Ole proteins were tagged. Hydrocarbon biosynthetic activity of copurified OleBCD assemblies could be reconstituted by adding separately purified OleA. Immunoblots of nondenaturing gels using anti-OleC reacted with X. campestris crude protein lysate indicated the presence of a large protein assembly containing OleC in the native host. Negative-stain electron microscopy of recombinant OleBCD revealed distinct large structures with diameters primarily between 24 and 40 nm. Assembling OleB, OleC, and OleD into a complex may be important to maintain stereochemical integrity of intermediates, facilitate the movement of hydrophobic metabolites between enzyme active sites, and protect the cell against the highly reactive β-lactone intermediate produced by the OleC-catalyzed reaction. IMPORTANCE Bacteria biosynthesize hydrophobic molecules to maintain a membrane, store carbon, and for antibiotics that help them survive in their niche. The hydrophobic compounds are often synthesized by a multidomain protein or by large multienzyme assemblies. The present study reports on the discovery that long-chain olefinic hydrocarbons made by bacteria from different phyla are produced by multienzyme assemblies in X. campestris. The OleBCD multienzyme assemblies are thought to compartmentalize and sequester olefin biosynthesis from the rest of the cell. This system provides additional insights into how bacteria control specific biosynthetic pathways.


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