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Hu L, Guan C, Zhao Y, Zhang W, Chai R, Teng J, Tian Q, Xun M, Wu F. Cloning, sequencing, expression, and purification of aspartic proteases isolated from two human Demodex species. Int J Biol Macromol 2023; 253:127404. [PMID: 37848116 DOI: 10.1016/j.ijbiomac.2023.127404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/22/2023] [Accepted: 10/10/2023] [Indexed: 10/19/2023]
Abstract
Aspartic proteases (ASPs) are important hydrolases for parasitic invasion of host tissues or cells. This was the first study on Demodex ASP. First, the complete coding sequence (CDS) was amplified, cloned and sequenced. Then, the protein physical and chemical properties was analysed. Finally, the recombinant plasmid, expression and purification system was established. Results showed that the lengths of CDS of Demodex folliculorum and D. brevis were 1161 and 1173 bp, respectively. The molecular weight of the protein was approximately 40 KDa. It contained an aspartic acid residue, a substrate-binding site and signal peptide, yet lacked a transmembrane domain and was located in the membrane or extracellular matrix. The phylogenetic and conserved motif analyses showed that D. folliculorum and D. brevis clustered separately and then formed a single branch, which finally clustered with other Acariformes species. The prokaryotic expression systems for recombinant ASP with His-tag (rASP-His) and GST-tag (rASP-GST) were constructed. The inclusion bodies of rASP-His were renaturated by gradient urea and purified using NI beads, while those of rASP-GST were renaturated by sarkosyl and Triton X-100 and purified using GST beads. Conclusively, the prokaryotic expression and purification system of Demodex rASP was successfully established for further pathogenic mechanism research.
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Affiliation(s)
- Li Hu
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Chenglin Guan
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Yae Zhao
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.
| | - Wanyu Zhang
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Rong Chai
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Juan Teng
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China; Linyi People's Hospital, Linyi, China
| | - Qiong Tian
- Department of Dermatology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Meng Xun
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Feng Wu
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
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Fernando DD, Reynolds SL, Zakrzewski M, Mofiz E, Papenfuss AT, Holt D, Fischer K. Phylogenetic relationships, stage-specific expression and localisation of a unique family of inactive cysteine proteases in Sarcoptes scabiei. Parasit Vectors 2018; 11:301. [PMID: 29769145 PMCID: PMC5956821 DOI: 10.1186/s13071-018-2862-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/23/2018] [Indexed: 11/17/2022] Open
Abstract
Background Scabies is worldwide one of the most common, yet neglected, parasitic skin infections, affecting a wide range of mammals including humans. Limited treatment options and evidence of emerging mite resistance against the currently used drugs drive our research to explore new therapeutic candidates. Previously, we discovered a multicopy family of genes encoding cysteine proteases with their catalytic sites inactivated by mutation (SMIPP-Cs). This protein family is unique in parasitic scabies mites and is absent in related non-burrowing mites. We postulated that the SMIPP-Cs have evolved as an adaptation to the parasitic lifestyle of the scabies mite. To formulate testable hypotheses for their functions and to propose possible strategies for translational research we investigated whether the SMIPP-Cs are common to all scabies mite varieties and where within the mite body as well as when throughout the parasitic life-cycle they are expressed. Results SMIPP-C sequences from human, pig and dog mites were analysed bioinformatically and the phylogenetic relationships between the SMIPP-C multi-copy gene families of human, pig and dog mites were established. Results suggest that amplification of the SMIPP-C genes occurred in a common ancestor and individual genes evolved independently in the different mite varieties. Recombinant human mite SMIPP-C proteins were produced and used for murine polyclonal antibody production. Immunohistology on skin sections from human patients localised the SMIPP-Cs in the mite gut and in mite faeces within in the epidermal skin burrows. SMIPP-C transcription into mRNA in different life stages was assessed in human and pig mites by reverse transcription followed by droplet digital PCR (ddPCR). High transcription levels of SMIPP-C genes were detected in the adult female life stage in comparison to all other life stages. Conclusions The fact that the SMIPP-Cs are unique to three Sarcoptes varieties, present in all burrowing life stages and highly expressed in the digestive system of the infective adult female life stage may highlight an essential role in parasitism. As they are excreted from the gut in scybala they presumably are able to interact or interfere with host proteins present in the epidermis. Electronic supplementary material The online version of this article (10.1186/s13071-018-2862-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Deepani D Fernando
- QIMR Berghofer Medical Research Institute, Infectious Diseases Program, 300 Herston Road, Herston, Brisbane, QLD, 4006, Australia.,School of Veterinary Sciences, University of Queensland, Gatton, QLD, 4343, Australia.,Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka
| | - Simone L Reynolds
- QIMR Berghofer Medical Research Institute, Infectious Diseases Program, 300 Herston Road, Herston, Brisbane, QLD, 4006, Australia
| | - Martha Zakrzewski
- QIMR Berghofer Medical Research Institute, Infectious Diseases Program, 300 Herston Road, Herston, Brisbane, QLD, 4006, Australia
| | - Ehtesham Mofiz
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Anthony T Papenfuss
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Peter MacCallum Cancer Centre, Victorian Comprehensive Cancer Centre, Melbourne, 3000, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Deborah Holt
- Menzies School of Health Research, Charles Darwin University, Casuarina, Northern Territory, Australia
| | - Katja Fischer
- QIMR Berghofer Medical Research Institute, Infectious Diseases Program, 300 Herston Road, Herston, Brisbane, QLD, 4006, Australia.
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Stoeckli MR, McNeilly TN, Frew D, Marr EJ, Nisbet AJ, van den Broek AHM, Burgess STG. The effect of Psoroptes ovis infestation on ovine epidermal barrier function. Vet Res 2013; 44:11. [PMID: 23398847 PMCID: PMC3599485 DOI: 10.1186/1297-9716-44-11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 01/11/2013] [Indexed: 11/10/2022] Open
Abstract
Sheep scab is an intensively pruritic, exudative and allergic dermatitis of sheep caused by the ectoparasitic mite Psoroptes ovis. The purpose of the present study was to investigate the effect of P. ovis infestation on different components of the ovine epidermal barrier within the first 24 hours post-infestation (hpi). To achieve this, the expression of epidermal differentiation complex (EDC) genes and epidermal barrier proteins, the nature and severity of epidermal pathology and transepidermal water loss (TEWL) were evaluated. By 1 hpi a significant dermal polymorphonuclear infiltrate and a significant increase in TEWL with maximal mean TEWL (598.67 g/m2h) were observed. Epidermal pathology involving intra-epidermal pustulation, loss of epidermal architecture and damage to the basement membrane was seen by 3 hpi. Filaggrin and loricrin protein levels in the stratum corneum declined significantly in the first 24 hpi and qPCR validation confirmed the decrease in expression of the key EDC genes involucrin, filaggrin and loricrin observed by microarray analysis, with 5.8-fold, 4.5-fold and 80-fold decreases, respectively by 24 hpi. The present study has demonstrated that early P. ovis infestation disrupts the ovine epidermal barrier causing significant alterations in the expression of critical barrier components, epidermal pathology, and TEWL. Many of these features have also been documented in human and canine atopic dermatitis suggesting that sheep scab may provide a model for the elucidation of events occurring in the early phases of atopic sensitisation.
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Affiliation(s)
- Miriam R Stoeckli
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, United Kingdom.
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Abstract
Psoroptic mange is one of the most severe skin conditions of sheep. This highly contagious disease is responsible for huge economical losses in many sheep-raising countries. It is also a significant welfare concern. Our understanding of the biology of Psoroptes ovis and of the host-parasite relationship during psoroptic mange made remarkable progress during the last decade. These data combined with the availability of powerful molecular tools have opened new avenues of research. Clearly, there is still a long way to go before a vaccine becomes a reality. Additionally, other diagnostic tools and control methods should be further investigated such as breeding for genetic resistance and the use of biocontrol agents.
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Affiliation(s)
- Bertrand Jacques Losson
- Laboratory of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, Bd de Colonster 20, 4000 Liège, Belgium.
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McNair CM, Billingsley PF, Nisbet AJ, Knox DP. Feeding-associated gene expression in sheep scab mites (Psoroptes ovis). Vet Res 2009; 41:16. [PMID: 19852923 PMCID: PMC2789330 DOI: 10.1051/vetres/2009064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 10/22/2009] [Indexed: 11/14/2022] Open
Abstract
The mite Psoroptes ovis is the causative agent of sheep scab. Although not usually fatal, the disease can spread rapidly and is a serious animal welfare concern. Vaccine development against ectoparasites has primarily focussed on two sources of candidate vaccine antigens – “exposed” antigens that are secreted in saliva during feeding on a host and “concealed” antigens that are usually expressed in the parasite gut and may be involved in digestion. Here, we sought to identify genes encoding proteins important for mite feeding and digestion by a subtractive suppressive hybridisation approach comparing mRNA transcript abundance in “fed” and “starved” mites. The study identified a variety of genes which are up-regulated by feeding mites. These included group 1, 5, 7 and 13 allergens including the previously described cysteine protease Pso o 1. In addition, numerous novel genes were identified here including some encoding potential salivary gland proteins and others encoding proteins which may facilitate feeding such as a serum opacity factor. An olfactory receptor-like protein was identified in the starved mite population which may help the mite to identify a host.
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Affiliation(s)
- Carol M McNair
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, nr Edinburgh EH26 0PZ, United Kingdom
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Watkins CA, Mackellar A, Frew D, Mackie C, George A, Hopkins J, Burgess STG, McNeilly TN, Huntley JF. Gene expression profiling of ovine keratinocytes stimulated with Psoroptes ovis mite antigen--a preliminary study. Parasite Immunol 2009; 31:304-11. [PMID: 19493210 DOI: 10.1111/j.1365-3024.2009.01103.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Sheep scab is caused by the noninvasive mite, Psoroptes ovis, which initiates a profound pro-inflammatory skin response leading to lesion development. To investigate these early events between the skin and the parasite, primary ovine epidermal keratinocyte cultures were generated and challenged with mite derived antigens. The kinetics of the mRNA response of these cells were monitored by microarray. The results indicated that the cells responded within 1 h of challenge, with a significant increase in the pro-inflammatory cytokine IL-8. This result was confirmed by real-time RT-PCR, and showed that IL-8 up-regulation was maximal at 1 h but declined to pre-stimulation levels at 24 and 48 h. The IL-8 mRNA response to mite wash antigens containing secretory and/or excretory proteins was also investigated and compared to the response to whole mite antigen. These studies revealed that the mite wash antigen, at a challenge dose of 10 microg/mL, was markedly more potent and induced significantly higher levels of IL-8 mRNA than the same concentration of whole mite antigen. These results are discussed in relation to mite establishment and survival on the ovine host.
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Affiliation(s)
- C A Watkins
- Moredun Research Institute, Pentland Science Park, Bush Loan, Penicuik, Midlothian, UK
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Hamilton KA, Nisbet AJ, Lehane MJ, Taylor MA, Billingsley PF. A physiological and biochemical model for digestion in the ectoparasitic mite, Psoroptes ovis (Acari: Psoroptidae). Int J Parasitol 2003; 33:773-85. [PMID: 12865077 DOI: 10.1016/s0020-7519(03)00089-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mites are an important group of arthropod pests affecting crops, animals and humans. Despite this, detailed physiological studies on these organisms remain sparse due largely to their small size. Unifying models are required to draw together the diverse information from studies on different groups and species. This paper describes a model for digestion in the parasitic mite, Psoroptes ovis, the causative agent of psoroptic mange or sheep scab disease. The limited information about this species is supplemented with data from other acarines, especially house dust mites and ticks. We review the range of enzymes and allergens found in mites and consider their possible roles in digestion in mites, generally and in particular, P. ovis. Histological studies, enzyme biochemistry and molecular biology and experimental evidence suggest that P. ovis utilises a digestive system reliant upon acid peptidases functioning in a largely intracellular environment. The actions of the digestive enzymes are supplemented by the involvement of bacteria as potential direct and indirect sources of nutrition. It is possible that some extra-corporeal digestion also takes place. The interaction of bacteria and digestive enzymes on the skin surface of the sheep may be responsible for the excessive pathological reactions evident in clinical sheep scab.
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Affiliation(s)
- K A Hamilton
- Department of Zoology, University of Aberdeen, Tillydrone Ave., Aberdeen AB24 2TZ, Scotland, UK
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Affiliation(s)
- A H van den Broek
- Department of Veterinary Clinical Studies, Royal School of Veterinaary Studies, University of Edimburgh, Easter Bush Veterinary Centre, Roslin, Midlothian EH 9RG
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Nisbet AJ, Billingsley PF. Characterisation of aminopeptidase activity in scab mites (Psoroptes spp.). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2002; 32:1123-1131. [PMID: 12213247 DOI: 10.1016/s0965-1748(02)00048-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Soluble and membrane-bound aminopeptidase activities were demonstrated in extracts of P. cuniculi (Delafond). Leucine aminopeptidase (LAP) activity in the soluble fraction of P. cuniculi extracts displayed substrate preference for amino acid derivatives with terminal leucine and methionine over those with acidic, basic or heterocyclic groups. P. cuniculi LAP was inhibited by leucinethiol (IC(50) = 1.4 +/- 0.4 nM), bestatin (IC(50) = 3.9 +/- 1.7 microM), Arphamenine A (IC(50) = 0.37 +/- 0.03 mM) the chelating agent 1,10-phenanthroline (IC(50) = 2.3 +/- 0.5 mM), Zn(2+), Cu(2+) Ni(2+), and Co(2+), and activated by Mn(2+) and Mg(2+). The LAP activity was visualised as a single major band after electrophoresis on native gels and eluted from a size exclusion column as a single major peak representing a molecular mass range of 85-116 kDa. Degenerate oligonucleotide primers were used to amplify short fragments of genomic DNA containing nucleotide sequence coding for the cation-binding motifs of the co-catalytic Zn(2+) binding domains of dizinc leucine aminopeptidases in both P. cuniculi and P.ovis (Hering). The major soluble aminopeptidase from these mites therefore displays most of the characteristics associated with typical cytosolic leucine aminopeptidases belonging to the M17 family of metalloproteinases.
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Affiliation(s)
- A J Nisbet
- Department of Zoology, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
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10
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Kenyon F, Knox D. The proteinases of Psoroptes ovis, the sheep scab mite--their diversity and substrate specificity. Vet Parasitol 2002; 105:317-25. [PMID: 11983306 DOI: 10.1016/s0304-4017(02)00015-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The sheep scab mite, Psoroptes ovis, causes severe dermatitis in infected sheep with severe welfare and production implications. The dermatitis has the characteristics of an immediate hypersensitivity type reaction which, by analogy to other mite species, including the house dust mites (Dermatophagoides spp.), is likely to be invoked by a variety of allergens including mite-derived proteinases. Here, the proteinases in P. ovis extracts were characterised using substrate gel analysis, inhibitor sensitivity and their ability to degrade a variety of potential natural protein substrates. These analyses showed that mites contain several proteinases which could be differentiated on the basis of molecular size and inhibitor sensitivity with cysteine, metalloproteinases and aspartyl proteinases predominating. These proteinases degraded collagen and fibronectin, possibly indicative of a role in lesion initiation, they degraded several blood proteins, a property which may aid mite feeding and they degraded immunoglobulin G, possibly aiding immuno-evasion. Because proteinases, particularly the cysteine class, are demonstrably allergenic in other mite infestations, these proteinases clearly merit further immunological and biochemical definition.
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Affiliation(s)
- Fiona Kenyon
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
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Smith WD, van den Broek A, Huntley J, Pettit D, Machell J, Miller HR, Bates P, Taylor M. Approaches to vaccines for Psoroptes ovis (sheep scab). Res Vet Sci 2001; 70:87-91. [PMID: 11170859 DOI: 10.1053/rvsc.2000.0427] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A brief outline of the history of sheep scab in the UK is presented together with the current chemical methods used for its control and problems associated with these. Possible alternative approaches to control are discussed, as are selected aspects of the physiology of Psoroptes ovis and the pathogenesis of the scab lesion from the perspective of control through immunisation. Evidence is provided that immunity to the disease can indeed be acquired, both naturally after a previous infection and following inoculation of mite proteins in adjuvant. These results support the view that control by vaccination may be possible, although little is known to date about the antigens involved or the mechanism of protection.
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Affiliation(s)
- W D Smith
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, Scotland, UK.
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Pettit D, Smith WD, Richardson J, Munn EA. Localisation and characterisation of ovine immunglobulin within the sheep scab mite, Psoroptes ovis. Vet Parasitol 2000; 89:231-9. [PMID: 10760413 DOI: 10.1016/s0304-4017(00)00203-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ovine IgG was detected in homogenates of repeatedly washed Psoroptes ovis. Some of the immunoglobulin in the homogenates was fragmented although the host IgG present in mite washings was largely intact. The host immunoglobulin was immuno-localised to the surface or cytoplasm of the gut cells of feeding stages of freshly harvested P. ovis examined by cryosectioning. A similar distribution of rabbit IgG was detected in P. cuniculi. The IgG demonstrated in the mite gut represented partially digested as well as intact immunoglobulin. The presence of intact host immunoglobulin suggests that P. ovis may be susceptible to vaccination by the gut antigen approach, a method used successfully for blood-feeding ectoparasites like Boophilus microplus.
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Affiliation(s)
- D Pettit
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK
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Nisbet AJ, Billingsley PF. A comparative survey of the hydrolytic enzymes of ectoparasitic and free-living mites. Int J Parasitol 2000; 30:19-27. [PMID: 10675740 DOI: 10.1016/s0020-7519(99)00169-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Extracts of ectoparasitic mites of birds (Dermanyssus gallinae), sheep (Psoroptes ovis) and plants (Tetranychus urticae) and of free-living mites (Acarus siro) contained acid and alkaline phosphatase, C4 and C8 esterases, lipase, leucine and valine aminopeptidases and a range of glycosidase activities. Dermanyssus gallinae and P. ovis, species highly adapted to an animal parasitic lifestyle, had very similar profiles and contained low activities of glycosidases. In contrast, the polyphagous species A. siro contained moderate to high activities of every glycosidase examined, whereas the phytophagous species, T. urticae, displayed high activities of only beta-galactosidase and beta-glucuronidase. All extracts hydrolysed haemoglobin with optima below pH6, and this hydrolysis was associated with an aspartic proteinase and variable cysteine proteinase activity dependent on species. Inhibitor-labelling with biotinyl-Phe-Ala-FMK revealed the presence of cysteine proteinases with molecular masses of 25-33.5kDa. Each mite species contains the enzymes necessary to complete digestion of the diet in the intracellular lysosomal compartment. The absolute and relative activities of each enzyme varied, and are discussed according to phylogeny and dietary habit.
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Affiliation(s)
- A J Nisbet
- Department of Zoology, University of Aberdeen, Tillydrone Avenue, Aberdeen, UK
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