Juvenile hormone (JH) regulates development and reproductive maturation in insects. The corpora allata (CA) from female adult mosquitoes synthesize fluctuating levels of JH, which have been linked to ...the ovarian development and are influenced by nutritional signals. The rate of JH biosynthesis is controlled by the rate of flux of isoprenoids in the pathway, which is the outcome of a complex interplay of changes in precursor pools and enzyme levels. A comprehensive study of the changes in enzymatic activities and precursor pool sizes have been previously reported for the mosquito Aedes aegypti JH biosynthesis pathway. In the present studies, we used two different quantitative approaches to describe and predict how changes in the individual metabolic reactions in the pathway affect JH synthesis. First, we constructed generalized additive models (GAMs) that described the association between changes in specific metabolite concentrations with changes in enzymatic activities and substrate concentrations. Changes in substrate concentrations explained 50% or more of the model deviances in 7 of the 13 metabolic steps analyzed. Addition of information on enzymatic activities almost always improved the fitness of GAMs built solely based on substrate concentrations. GAMs were validated using experimental data that were not included when the model was built. In addition, a system of ordinary differential equations (ODE) was developed to describe the instantaneous changes in metabolites as a function of the levels of enzymatic catalytic activities. The results demonstrated the ability of the models to predict changes in the flux of metabolites in the JH pathway, and can be used in the future to design and validate experimental manipulations of JH synthesis.
Ocean organisms live in competitive environments that demand the production of poisons and toxins. In some cases, these substances have been used in the pharmaceutical industry for human disease ...treatments. Most fish poisons generally have potent cytolytic activity, probably through cardiovascular and neuromuscular effects. In the case of marine stingrays, the injuries made by their tail venom apparatus are caused by the mechanical penetration of their sting and a subsequent venom release. This study focused on the evaluation of substances with cytotoxic activity in the epithelium that covers the venom apparatus from the marine stingray Hypanus dipterurus. To demonstrate the above, the hemolytic, proteolytic and cytotoxic capacities of H. dipterurus epithelium substances were determined. Discs impregnated with epithelial extract were used on blood agar plates. The proteolytic activity was analyzed using casein as substrate and for gelatin the liquefaction activity test. To determine the cytotoxicity degree of the extracts, the proliferation and cell viability MTT bioassay was implemented on human cervical carcinoma cells (HeLa). The results showed that no hemolytic or proteolytic activity existed against casein associated with the epithelial extract, but gelatin hydrolysis and cytotoxic activity against the HeLa cell line were observed. This study concludes that the substances found in the epithelium covering the H. dipterurus stingray venom apparatus are a mixture of various proteins, among which, glycosylated anionic proteins represent a potential source of molecules with cytotoxic and hydrolytic activity.
•Hemolytic, proteolytic and cytotoxic capacities of Hypanus dipterurus epithelium substances were determined.•No hemolytic or proteolytic activity existed against casein associated with the Hypanus dipterurus epithelium extract.•Hydrolysis and cytotoxic activity against the HeLa cell line were observed from Hypanus dipterurus epithelium extract.•Hypanus dipterurus venom apparatus contained a mixture of several proteins, including a glycosylated anionic protein.
During shrimp larval development, changes occur in molecular components. Enzyme activity and mRNA expression of proteinases were assayed in Penaeus vannamei during larval development, which consists ...of 5 nauplius stages, 3 protozoeal stages, 3 mysis stages, and 12 postlarval stages. Trypsin activity reached a maximum at the beginning of postlarval stages 1 and 2, and significantly decreased in subsequent postlarval stages. Chymotrypsin activity increased at the third protozoeal stage, then significantly decreased in subsequent stages. Identification of proteinase by mass spectrometry and inhibitors allowed us to track their appearance in zymograms and to distinguish between isoenzymes. Chymotrypsin BI and BII had a distinguishing pattern of appearance during larval development, which could compensate for the reduction in trypsin activity. The mRNA content of isotrypsin 21, chymotrypsin 1, and zinc proteinase was differentially expressed in larvae. Zinc proteinase and chymotrypsin 1 mRNA were expressed at a basal content at the beginning of the protozoeal stages, increased by the end of the mysis stages and onward, while isotrypsin 21 mRNA had a peak at mysis stage 3. Transcript changes reflect transcriptional regulation of the proteinases tested. Proteinase mRNA in tissues, other than the digestive gland, suggests potentially different roles besides digestion during ontogeny.
Abstract
Bioactive peptides have been studied in several sources due to their valuable potential in the pharmaceutical and food industries. Abalone viscera, which are normally discarded as ...byproducts, are a rich source of protein. Thus, the aim of this study was to explore the potential bioactivity of peptides derived from abalone viscera (
Haliotis fulgens
and
Haliotis corrugata
) after hydrolysis with a commercial mixture of enzymes. The hydrolysates obtained were fractionated using gel filtration chromatography. The resulting hydrolysate fractions were investigated for their antimicrobial and cytotoxic activities, including the expression of gelatinases
mmp-2
and
mmp-9
in human prostate cancer cell lines (PC3). Results showed antimicrobial activity for protein fractions of
H. corrugata
against
Proteus mirabilis
and
Pseudomona aeuroginosa
(66.2–116.25 kDa),
Bacillus subtilis
(6.5–21.5 kDa), and
Aspergillus niger
(97.4–116.25 kDa), while
H. fulgens
peptide fractions (200–31 kDa) displayed activity against six bacterial strains, and fractions from 116.25 to 21.5 kDa had effects on the fungus
A. niger
,
Alternaria alternata
, and
Aspergillus flavus
. Additionally, protein fractions displayed cytotoxic activity, inhibiting 30.4–53.8% of PC3 cellular growth. Selected fractions decreased the PMA-induced and not-induced expressions of
mmp-2
and
mmp-9
in PC3 cells. Abalone viscera, as byproducts, can be used as a potential source of antimicrobial and anticancer peptides.
Shell matrix proteins (SMPs) are key components for the Mollusk shell biomineralization. SMPs function has been hypothesized in several proteins by bioinformatics analysis, and through in vitro ...crystallization assays. However, studies of the post-translational modifications (PTMs) of SMPs, which contribute to their structure and the function, are limited. This review provides the current status of the SMPs with the most common PTMs described (glycosylation, phosphorylation, and disulfide bond formation) and their role in shell biomineralization. Also, recent studies based on recombinant production of SMPs are discussed. Finally, recommendations for the study of SMPs and their PTMs are provided. The review showed that PTMs are widely distributed in SMPs, and their presence on SMPs may contribute to the modulation of their activity in some SMPs, contributing to the crystal growth formation and differentiation through different mechanisms, however, in a few cases the lack of the PTMs do not alter their inherent function.
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•SMPs possess one or several post-translational modifications (e.g. glycosylation, phosphorylation, disulfide bonds and sulfation).•Post-translational modifications of shell matrix proteins modulate their activity.•Post-translational modifications of shell matrix proteins contribute to crystal differentiation.
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•Non-energetic nutrients or micronutrients are essential for mosquito physiology.•Free amino acids play important roles in digestion, flight physiology and ammonia ...detoxification.•Metal, sterol and vitamin homeostasis are critical for cell signaling, respiration, metabolism and reproduction.•Micronutrient homeostasis influences the symbiotic relationships with microorganisms.
Micronutrients or non-energetic nutrients (NEN) are needed in reduced amounts, but are essential for many mosquito physiological processes that influence biological traits from vector competence to reproductive capacity. The NEN include amino acids (AA), vitamins, salts, metals and sterols. Free AA plays critical roles controlling most physiological processes, from digestion to reproduction. Particularly proline connects metabolic pathways in energy production, flight physiology and ammonia detoxification. Metal, in particular iron and calcium, salts, sterol and vitamin homeostasis are critical for cell signaling, respiration, metabolism and reproduction. Micronutrient homeostasis influence the symbiotic relationships with microorganisms, having important implications in mosquitoes’ nutrition, physiology and behavior, as well as in mosquito immunity and vector competence.
An acidic protein, Hf15, from Haliotis fulgens involved in biomineralization Rivera-Pérez, Crisalejandra; Arroyo-Loranca, Raquel G.; Hernández-Saavedra, Norma Yolanda
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology,
October 2022, 2022-10-00, 20221001, Letnik:
272
Journal Article
Recenzirano
Biomineralization leads to the hardening of mineralized materials, such as the shell of Mollusk, to fulfill a wide range of functions, such as (but not limited to) skeletal support, protection of the ...soft tissues, navigation, etc. The study of the proteins responsible for this process, shell matrix proteins (SMPs), allows addressing questions related to structure-function relationship and to the mechanism of mineral formation, which is limited in gastropod species. In this study, a low molecular weight protein was isolated from the insoluble fraction after decalcification with acetic acid of the shell of Haliotis fulgens and, named Hf15. The unglycosylated protein has a theoretical molecular weight of 15 kDa, it possesses calcium and chiting binding properties. Hf15 can precipitate calcium carbonate in vitro in presence of different salts. Analysis by LC-MS of the five peptide sequences of Hf15 generated by trypsinization revealed that two peptides displayed homology to an uncharacterized protein 3-like from Haliotis rufescens, Haliotis asinia and H. sorenseni. The results obtained indicated that Hf15 is a novel SMP involved in shell mineralization in Haliotis fulgens.
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•Hf15 is a novel SMP involved in shell mineralization.•Hf15 is an acidic unglycosylated protein with calcium and chitin-binding capability.•Hf15 has no homology to previously characterized SMPs.
Fatty acid desaturases are key enzymes involved in unsaturated fatty acid biosynthesis, which insert double bonds at specific positions of fatty acids, playing a pivotal role in unsaturated fatty ...acid synthesis required for membrane lipid fluidity. The ∆5 and ∆6 desaturases are responsible for producing long chain-polyunsaturated fatty acids (LC-PUFA) through their precursors α-linolenic acid and linoleic acid in organisms lacking or with very low ability to synthesize LC-PUFA by themselves. Extensive studies of fatty acid desaturases are available in model organisms, such as humans and mouse; however, the diversity of these genes in the marine biodiversity is less known. This study performed an exhaustive analysis to identify the ∆5 and ∆6 desaturases in the available marine genomes in databases, as well as transcriptomes and EST databases, and their coding sequences were compared to the well-characterized ∆5 and ∆6 desaturases from humans. The FADS1 and FADS2 genetic structures are well conserved among all the organisms analyzed. A common amino acid pattern was identified to discriminate between ∆5 and ∆6 desaturases. The analysis of the conserved motif involved in catalysis showed that 20% of the desaturases, ∆5 and ∆6, have lost motifs required for catalysis. Additionally, bifunctional ∆5/∆6 desaturases were able to be identified by amino acid sequence patterns found in previously described enzymes. A revision of the expression profiles and functional activity on sequences in databases and scientific literature provided information regarding the function of these marine organism enzymes.
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•Marine fish do not possess FADS1 gene but possess several isoforms of FADS2 gene.•Mollusks do not have FADS2 gene in their genome.•Few-marine organisms present Δ5/Δ4 and Δ5/Δ6 bifunctional desaturases.•The amino acids involved in the regioselectivity of the enzymes allow the distinction of Δ5 and Δ6 desaturases.•Bifunctional fatty acid Δ5/Δ6 desaturases can be predicted by amino acid sequence homology.
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