Prevalence alergických onemocnění celosvětově dramaticky stoupá. Mezi nejvýznamnější alergeny patří proteolytické enzymy (proteasy). Byly nalezeny jako alergeny hmyzího jedu, potravinové alergeny a velká skupina inhalačních alergenů, které pocházejí z roztočů, hmyzu, rostlinného pylu a spor hub. Proteasové alergeny patří do různých tříd proteolytických enzymů, a to cysteinových, serinových a aspartátových proteas. K jejich vysoké alergenicitě přispívá především enzymová aktivita, která se účastní několika fází patofyziologie hypersenzitivní reakce. Proteasy zároveň narušují buňky plicního epitelu a umožňují průnik také ostatním typům alergenů. V tomto přehledném článku jsou shrnuty dostupné poznatky o klasifikaci a funkci alergenních proteas.

The global prevalence of allergic diseases is dramatically increasing worldwide. Proteolytic enzymes (proteases) are among the most important allergens. They have been identified as insect venom allergens, food allergens, and a large group of inhalant allergens from mites, insects, plant pollen, and fungal spores. Protease allergens belong to different classes of proteolytic enzymes, including cysteine, serine and aspartic proteases. The enzymatic activity contributes to the high allergenicity of proteases and participates in several phases of pathophysiology of the hypersensitivity reaction. Proteases also play an important role in the disruption of the lung epithelial barrier and allow penetration of other types of allergens. This review article summarizes current knowledge on classification and function of allergenic proteases.

• MeSH
• alergeny * škodlivé účinky   MeSH
• alergie etiologie   MeSH
• antigeny roztočů domácího prachu škodlivé účinky   MeSH
• lidé MeSH
• proteasy škodlivé účinky   MeSH
• pyl MeSH
• roztoči MeSH
• švábi MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

Host blood proteins, represented mainly by hemoglobin and serum albumin, serve as the ultimate source of amino acids needed for de novo protein synthesis during tick development and reproduction. While uptake and processing of hemoglobin by tick gut cells have been studied in detail, molecular mechanisms of host serum albumin degradation remain unknown. In this work, we have used artificial membrane feeding of Ixodes ricinus females on a hemoglobin-free diet in order to characterize the proteolytic machinery involved in albuminolysis. Morphological comparisons of ticks fed on whole blood (BF) and serum (SF) at microscopic and ultrastructural levels showed that albumin and hemoglobin have different trafficking routes in tick gut cells. Analysis in vitro with selective inhibitors demonstrated that albumin is degraded at an acidic pH by a network of cysteine and aspartic peptidases with predominant involvement of cysteine cathepsins having endo- and exopeptidase activities. The cleavage map of albumin and the roles of individual peptidases in albumin degradation were determined. These results indicate that the albuminolytic pathway is controlled by the same proteolytic system that is responsible for hemoglobinolysis. This was further supported by the overall similarity of gut peptidase profiles in SF and BF ticks at the transcriptional and enzymatic activity levels. In conclusion, our work provides evidence that although hemoglobin and albumin are transported differentially during heterophagy they are digested by a common multienzyme proteolytic network. This central digestive system, critical for successful blood feeding in tick females, thus represents a valuable target for novel anti-tick interventions.

• MeSH
• aspartátové proteasy metabolismus   MeSH
• cysteinové proteasy metabolismus   MeSH
• hemoglobiny metabolismus   MeSH
• klíště enzymologie   MeSH
• koncentrace vodíkových iontů MeSH
• proteolýza * MeSH
• sérový albumin metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Labial glands are present in all castes and developmental stages of all termite species. In workers, their secretion contains a food-marking pheromone and digestive enzymes, while soldier secretion plays a defensive role. However, these functions were studied only in a limited set of species, and do not allow drawing general conclusions. Hence, we have investigated the chemical composition of the labial gland extracts from soldiers and workers in 15 termite species belonging to 6 families using an integrative approach based on proteomic and small-molecule profiling. We confirmed the presence of hydroquinone and cellulase in the labial glands of workers, and we identified new toxic compounds in soldiers and workers of several species. Our results highlight the dual role of labial gland secretion, i.e. the defensive role in soldiers and workers of several termite species, and the digestive function in workers.

• MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• exokrinní žlázy sekrece   MeSH
• hmyzí proteiny chemie   sekrece   MeSH
• Isoptera fyziologie   MeSH
• molekulární sekvence - údaje MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• sekvence aminokyselin MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

BACKGROUND: Enzymatic allergens of storage mites that contaminate stored food products are poorly characterized. We describe biochemical and immunological properties of the native alpha-amylase allergen Aca s 4 from Acarus siro, a medically important storage mite. RESULTS: A. siro produced a high level of alpha-amylase activity attributed to Aca s 4. This enzyme was purified and identified by protein sequencing and LC-MS/MS analysis. Aca s 4 showed a distinct inhibition pattern and an unusual alpha-amylolytic activity with low sensitivity to activation by chloride ions. Homology modeling of Aca s 4 revealed a structural change in the chloride-binding site that may account for this activation pattern. Aca s 4 was recognized by IgE from house dust mite-sensitive patients, and potential epitopes for cross-reactivity with house dust mite group 4 allergens were found. CONCLUSIONS: We present the first protein-level characterization of a group 4 allergen from storage mites. Due to its high production and IgE reactivity, Aca s 4 is potentially relevant to allergic hypersensitivity.

• MeSH
• Acaridae enzymologie   imunologie   MeSH
• alergeny chemie   imunologie   izolace a purifikace   MeSH
• alergie krev   imunologie   MeSH
• alfa-amylasy chemie   imunologie   izolace a purifikace   MeSH
• feces chemie   MeSH
• hmyzí proteiny chemie   imunologie   izolace a purifikace   MeSH
• imunoglobulin E krev   MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• strukturní homologie proteinů MeSH
• terciární struktura proteinů MeSH
• vazba proteinů MeSH
• zkřížené reakce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH