Preliminary Study on Biological Characteristics of Degraded Soil Ecosystems in Dry Hot Valley of the Jinsha River

Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jinsha River, China. Results showed that Hymenoptera, Araneae and Collembola were the dominant groups of soil animals in the plots studied. The numbers of groups and individuals and density of soil animals in the dry red soil series were higher than those in the Vertisol series, and the numbers of individuals and density of soil animals decreased with the degree of soil degradation. Bacteria dominated microbiocoenosis not only in the dry red soils but also in the Vertisols. Microbial numbers of the dry red soil series were higher than those of Vertisol series, and decreased with the degree of soil degradation. The activities of catalase, invertase, urease and alkaline phosphatase declined with the degradation degree and showed a significant decline with depth in the profiles of both the dry red soils and the Vertisols, but activities of polyphenol oxidase and acid and neutral phosphatase showed the same tendencies only in the Vertisols. It was concluded that the characteristics of soil animals, microorganisms and enzymatic activity could be used as the bio-indicators to show the degradation degree of the dry red soils and Vertisols. Correlation among these soil bio-indicators was highly significant.

Reduction in Activity/Gene Expression of Anthocyanin Degradation Enzymes in Lychee Pericarp is Responsible for the Color Protection of the Fruit by Heat and Acid Treatment

Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee （Litchi chinensis） fruits, but the mechanism was not clear. In the present study, hot water （70℃） dipping followed by immersion in 2% HC1 （heat-acid） substantially protected the red color of the fruit during storage at 25℃ and inhibited anthocyanin degradation while hot water dipping alone （heat） led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme （ADE）, peroxidase （POD） and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee pericarp.

The Mechanism of Carotenoid Degradation in Flue-Cured Tobacco and Changes in the Related Enzyme Activities at the Leaf-Drying Stage During the Bulk Curing Process

The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical basis for optimization of curing technology. The effect of different rising speeds of temperature on the carotenoid degradation and the related enzymes activities at the color-fixing stage during the bulk curing process was studied by using the electric-heated fluecuring barn designed by Henan Agricultural University, China, based on curing technology with yellowing at low temperature and moderate humidity and leaf drying at moderate humidity. The results showed that the carotenoid degradation components （β-carotene, lutein, neoxanthin, and violaxthin） decreased gradually at the color-fixing stage during the bulk curing process. The carotenoid degradation components viz.,β-carotene, lutein, neoxanthin, and violaxthin at the slow heating curing （T1） were relatively higher than the rapid heating curing （T2） accounting for 10, 2, 32 and 32% respectively, but there were no differences among treatments （P〉 0.05）. The effect of different conditions of curing on the activities of enzymes related to carotenoids degradation were significant. The lipoxygenase, phenylalanine ammonialyase, peroxidase, and polyphenol oxidase enzymes had a bidirectional effect on the quality of tobacco leaves and it was beneficial to form more premise matter of aroma based on the higher enzyme activities at the early leaf-drying stage. The slow heating could regulate the change in various enzymes＇ activities reasonably, making cell redox reaction to reach the dynamic balance and make the degradation of carotenoids adequately. Meanwhile, it could avoid the occurrence of browning reaction and provide foundation for improving the quality of tobacco and optimization of technology for bulk curing and further enhancing aroma.

Dietary protein levels changed the hardness of muscle by acting on muscle fiber growth and the metabolism of collagen in sub-adult grass carp(Ctenopharyngodon idella)

Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is expensive.Although our team found that the effect of protein on the muscle hardness of grass carp was probably related to an increased collagen content,the mechanism for this effect has not been deeply explored.Moreover,few studies have explored the protein requirements of sub-adult grass crap(Ctenopharyngodon idella).Therefore,the effects of different dietary protein levels on the growth performance,nutritional value,muscle hardness,muscle fiber growth,collagen metabolism and related molecule expression in grass carp were investigated.Methods:A total of 450 healthy grass carp(721.16±1.98 g)were selected and assigned randomly to six experimen-tal groups with three replicates each(n=25/replicate),and were fed six diets with 15.91%,19.39%,22.10%,25.59%,28.53%and 31.42%protein for 60 d.Results:Appropriate levels of dietary protein increased the feed intake,percentage weight gain,specific growth rate,body composition,unsaturated fatty acid content in muscle,partial free amino acid content in muscle,and muscle hardness of grass carp.These protein levels also increased the muscle fiber density,the frequency of new muscle fibers,the contents of collagen and IGF-1,and the enzyme activities of prolyl 4-hydroxylases and lysyloxidase,and decreased the activity of matrix metalloproteinase-2.At the molecular level,the optimal dietary protein increased col-lagen type Iα1(Colα1),Colα2,PI3K,Akt,S6K1,La ribonucleoprotein domain family member 6a(LARP6a),TGF-β1,Smad2,Smad4,Smad3,tissue inhibitor of metalloproteinase-2,MyoD,Myf5,MyoG and MyHC relative mRNA levels.The levels of the myostatin-1 and myostatin-2 genes were downregulated,and the protein expression levels of p-Smad2,Smad2,Smad4,p-Akt,Akt,LARP6 and Smad3 were increased.Conclusions:The appropriate levels of dietary protein promoted the growth of sub-adult grass carp and improved muscle hardness by promoting the growth of muscle fibers,improving collagen synthesis and depressing collagen degradation.In addition,the dietary protein requirements of sub-adult grass carp were 26.21%and 24.85%according to the quadratic regression analysis of growth performance(SGR)and the muscle hardness(collagen content),respectively.

Molecular mechanism of the inhibition effect of Celecoxib on corneal collagen degradation in three dimensions

AIM: To clarify the molecular mechanism of Celecoxib on corneal collagen degradation and corneal ulcer. METHODS: Rabbit corneal fibroblasts were harvested and suspended in serum-free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidify in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP1, 3 and TIMP1, 2 was performed. MMP2, 9 was detected by the method of Gelatin zymography. Cytotoxicity Assay was measured. RESULTS: Celecoxib inhibited corneal collagen degradation in a dose and time manner; Celecoxib inhibited the IL-1 beta induced increases in proMMP1, 2, 3, 9 and active MMP1, 2, 3, 9 in a concentration-depended manner. Celecoxib can also inhibit the IL-1 beta induced increases in the TIMP1, 2. CONCLUSION: Celecoxib can inhibit corneal collagen degradation induced by IL-1 beta, this effect is the consequence of the reduction of MMP1, 2, 3, 9 and TIMP1, 2. The results of the present study provide new insight into Celecoxib in cornela ulcer treatment.

Pathogenicity of Cell Wall Degrading Enzymes Produced by Botryodiplodia theobromae Pat. against Mangoes

[ Objective ] This study aimed to confirm the roles of cell wall degrading enzymes （CWDEs） produced by Botryodiplodia theobromae Pat. in the infec- tion of mango fruits. [ Method] Change of activities of five types of CWDEs produced by B. theobromae Pat. were studied under both in vitro culture and inocula- tion conditions, along with the pathogenicity and the ability of producing CWDEs of four post-harvest fangal pathogens（B, theobromae Pat. , Colletotrichum gloeos- porioides Penz. , Phomopsis mangiferae Ahmad and Dothiorella dominicana Pet. et Cif. ） which cause stem-end rot of mangoes. [ Result] B. theobromae Pat. was a- ble to produce polygalacturonase（PG）, pectinmethylgalacturonase（PMG）, polygalacturonic acid trans-eliminase （PGTE）, pectin methyltrans-eliminase （PMTE） and cellulase （ Cx. ） under both in vitro culture and inoculation conditions, of which activities of PG, Cx and PMG were significantly higher in than that in either PGTE or PMTE. Among three primary CWDEs, the peak of activities of PG and Cx appeared earlier and that of PMG occured later. The pathogenicity of B. theo- bromae Pat. was significantly higher than that of any other three pathogens; it is the same with the abilities of producing pectinase. [ Conclusion] This paper pro- vides theoretical bases for further exploring the mechanism of host-pathogen interaction and decreasing the post-harvest loss of mango fruits.

Identification and Expression of Some Plant Cell Wall-Degrading Enzymes Present in Three Ontogenetics Stages of Thecaphora frezii, a Peanut (<i>Arachis hypogaea</i>L.) Pathogenic Fungus

Peanuts can be affected by the presence of pathogenic microorganisms. The fungus Thecaphora frezii (T. frezii), which belongs to the taxonomic class Ustilaginomycetes, is the causal agent of the disease known as “peanut smut”. The life cycle of this fungus includes three stages, namely teliospores, basidiospores and hyphae. In the hyphae stage, infection occurs in the peanut plant, which requires the involvement of some enzymes secreted by the fungus. These include the Plant Cell Wall-Degrading Enzymes (PCWDEs), which degrade various polysaccharides. This study aimed to identify the presence of transcript for enzymes belonging to the PCWDEs from three stages of T. frezii. For this, total RNA was extracted from the three ontogenetic stages of T. frezii. These samples were analyzed using an RNA-Seq approach and some transcripts were quantified using Real Time PCR. The analysis of the data provided by the RNA-Seq of the three T. frezii stages, it was possible to identify some transcripts that could encode enzymes compatible with polysaccharides degradation that are part of the plant cell wall. In T. frezii transcriptome, 40 deduced proteins would be enzymes with functions of PCWDEs were identified. They were divided into 27 glycoside hydrolases;two polysaccharide lyases;three carbohydrate esterases and eight enzymes with auxiliary activities. In addition, the fungal SNF1 gene was identified whose activity could be affected by high glucose level, and indirectly influence the levels of some PCWDEs. The analysis of the PCWDEs could help to understand part of the fungal infection process and possibly find substances that can control its development.

可可球二孢(Botryodiplodia theobromae)细胞壁降解酶对杧果果实致病作用

为明确可可球二孢(Botryodiplodia theobromae Pat.)产细胞壁降解酶在侵染杧果果实过程中的作用,研究了可可球二孢在离体培养和接种条件下分泌的5种细胞壁降解酶活性变化特点,以及可可球二孢(B.theobromae)、胶孢炭疽菌(Colletotrichum gloeosporioides Penz.)、杧果拟茎点霉(Phomopsis mangiferae Ahmad)和小穴壳菌(Dothiorella do-minicana Pet.et Cif.)4种杧果采后主要蒂腐病菌分泌细胞壁降解酶的能力。结果表明,可可球二孢在离体培养条件下或接种杧果果实后均可产生多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、多聚半乳糖醛酸反式消除酶(PGTE)、果胶甲基反式消除酶(PMTE),以及纤维素酶(Cx)。其中PG、PMG和Cx活性较高,PGTE和PMTE活性极低。在大量分泌的3种细胞壁降解酶中,PG和Cx活性高峰出现较早,PMG活性高峰出现较迟。可可球二孢的致病力显著高于胶孢炭疽菌、杧果拟茎点霉和小穴壳菌。其可可球二孢分泌果胶酶的能力也显著高于其他3种病菌。

血清β-crosslaps、Cathe K水平变化在骨质疏松症诊断中的应用价值

目的:探讨β-胶原降解产物(β-crosslaps)、血清组织蛋白酶K(Cathe K)在骨质疏松诊断中的应用价值。方法:选取接受骨密度检测的受试者289例,其中骨量正常者76例(骨量正常组),骨量减少者91例(骨量减少组),骨质疏松者122例(骨质疏松组),检测受试者β-crosslaps、Cathe K及骨密度(BMD)。结果:骨质疏松组β-crosslaps和Cathe K分别为(0.97±0.14)ng/mL和(35.22±9.76)ng/L,明显高于骨量正常组和骨量减少组(P<0.05);骨质疏松组BMD明显低于骨量减少组和骨量正常组(P<0.05),骨量减少组BMD低于骨量正常组(P<0.05);骨量正常组和骨量减少组β-crosslaps和Cathe K比较差异无统计学意义(P>0.05);β-crosslaps、Cathe K和BMD呈负相关(r=-0.344和-0.301,P<0.05),而β-crosslaps和Cathe K之间无相关性(P>0.05)。结论:血清-crosslaps、Cathe K在骨质疏松诊断中有一定的价值,其水平与骨密度有相关性。

血清β-CTX、Cathe K、OPG对老年OPF患者术后骨折再发的预测价值

目的探究血清β-胶原降解产物(β-CTX)、组织蛋白酶K(cathepsin K,Cathe K)和骨保护素(osteoprotegerin,OPG)对老年骨质疏松性骨折(osteoportic fracture,OPF)术后骨折再发的预测价值。方法选取2018年3月-2020年3月在中南大学湘雅医学院附属海口医院行经皮椎体成形术(percutaneous vertebroplasty,PVP)和经皮椎体后凸成形术(percutaneous kyphoplasty vertebroplasty,PKP)治疗的老年OPF患者120例,依据术后是否再发骨折分为再发骨折组(32例)和非再发骨折组(88例),检测并对比两组患者血清β-CTX、Cathe K、OPG水平及其他可能影响因素差异。采用Logistic回归分析明确影响老年OPF术后再发骨折的危险因素,并绘制受试者工作特征曲线(ROC)评价血清β-CTX、Cathe K、OPG水平对老年OPF患者再发骨折的预测价值。结果再发骨折组的骨折程度、血清β-CTX、Cathe K水平高于非再发骨折组,骨密度T值及血清OPG水平低于非再发骨折组(P<0.05)。Logistic回归分析显示,骨折程度、骨密度T值、β-CTX、Cathe K、OPG均是影响老年OPF患者术后再发骨折的危险因素(P<0.05)。ROC分析显示,血清β-CTX、Cathe K、OPG联合预测老年OPF患者术后再发骨折的灵敏度、特异度、AUC分别为87.50%、60.23%、0.859,均高于β-CTX、Cathe K、OPG单独预测。结论血清β-CTX、Cathe K、OPG在老年OPF术后再发骨折患者中的水平较高,是影响老年OPF术后再发骨折的危险因素,对老年OPF术后骨折再发的评估具有较高的临床价值。

Intranasal neprilysin rapidly eliminates amyloid-beta plaques, but causes plaque compensations: the explanation why the amyloid-beta cascade may fail?

Neurodegenerative brain disorders are a major burden in our society,such as Alzheimer´s disease.In order to repair or prevent such diseases,drugs are designed which enter the brain,but the blood-brain barrier limits their entry and the search for alternative pathways is important.Recently,we reported that intranasal delivery of the amyloid-beta degrading enzyme neprilysin eliminated amyloid-beta plaques in transgenic Alzheimer´s disease mice.This review describes the anatomical structure of the intranasal pathway,explains the intranasal delivery of pure neprilysin,cell-loaded neprilysin(platelets)and collagen-embedded neprilysin to destruct amyloid-beta plaques in Alzheimer´s disease in transgenic APP_SweDI mice and hypothesizes why this may cause compensation and why the amyloid-beta cascade hypothesis may fail.

Gene expression microarray analysis of the spinal trigeminal nucleus in a rat model of migraine with aura

Cortical spreading depression can trigger migraine with aura and activate the trigeminal vascular system. To examine gene expression profiles in the spinal trigeminal nucleus in rats following cortical spreading depression-induced migraine with aura, a rat model was established by injection of 1 M potassium chloride, which induced cortical spreading depression. DNA microarray analysis revealed that, compared with the control group, the cortical spreading depression group showed seven upregulated genes-myosin heavy chain 1/2, myosin light chain 1, myosin light chain （phosphorylatable, fast skeletal muscle）, actin alpha 1, homeobox B8, carbonic anhydrase 3 and an unknown gene. Two genes were downregulated-RGD1563441 and an unknown gene. Real-time quantitative reverse transcription-PCR and bioinformatics analysis indicated that these genes are involved in motility, cell migration, CO2/nitric oxide homeostasis and signal transduction.

Transcriptome exploration to provide a resource for the study of Auricularia heimuer

Auricularia heimuer,an edible jelly fungus,is in considerable demand in Asia due to its high nutritive,economic and medicinal values.RNA-Seq was used to investigate and analyze the mycelium transcriptome of A.heimuer for gene discovery.A total of 26,857 unigenes with an N50 length of 1333 bp were assembled by de novo sequencing.In addition,unigenes were annotated by publicly available databases,including gene descriptions,gene ontology(GO),clusters of orthologous group(COG),Kyoto Encyclopedia of Genes and Genomes(KEGG)metabolic pathways,and protein family(Pfam)terms.A.heimuer was also studied for its wood degradation ability.Thirty-eight putative FOLymes(fungal oxidative lignin enzymes)and 251 CAZymes(carbohydrate-active enzymes)were located from A.heimuer transcriptome.Our study provides a comprehensive sequence resource for A.heimuer at the transcriptional level,which will lay a strong foundation for functional genomics studies and gene discovery of this promising fungus.

绝经后骨质疏松症患者血清β-CTX、Cathe K和OPG水平变化及其临床意义

目的观察绝经后骨质疏松症(PMO)患者血清β胶原降解产物(β-CTX)、组织蛋白酶K(Cathe K)、骨保护素(OPG)水平变化,并探讨其临床意义。方法选择PMO患者64例(骨质疏松组),其中发生骨质疏松性骨折34例、未发生骨质疏松性骨折30例,另选绝经后骨量减少患者43例(骨量减少组)、绝经后骨量正常患者42例(骨量正常组)。所有研究对象入组后,采集肘静脉血,离心留取血清,检测血清β-CTX、Cathe K、OPG。采用受试者工作特征(ROC)曲线评估血清β-CTX、Cathe K、OPG水平预测PMO患者发生骨质疏松性骨折的效能。结果骨质疏松组与骨量减少组血清β-CTX、Cathe K水平均高于骨量正常组,血清OPG水平低于骨量正常组,且骨质疏松组血清β-CTX、Cathe K水平均高于骨量减少组,而骨质疏松组血清OPG水平低于骨量减少组(P均<0.05)。PMO患者发生骨质疏松性骨折者血清β-CTX、Cathe K水平均高于未发生骨质疏松性骨折者,而血清OPG水平低于未发生骨质疏松性骨折者(P均<0.05)。ROC曲线分析显示,血清β-CTX水平预测PMO患者发生骨质疏松性骨折的曲线下面积(AUC)为0.839(95%CI:0.756~0.903),其最佳截断值为7.84μg/L,此时其预测敏感性为77.8%、特异性为80.7%;血清Cathe K水平预测PMO患者发生骨质疏松性骨折的AUC为0.821(95%CI:0.735~0.889),其最佳截断值为33.04μg/L,此时其预测敏感性为68.3%、特异性为89.1%;血清OPG水平预测PMO患者发生骨质疏松性骨折的AUC为0.824(95%CI:0.739~0.891),其最佳截断值为3.12μg/L,此时其预测敏感性为78.8%、特异性为82.0%;血清β-CTX、Cathe K、OPG水平联合预测PMO患者发生骨质疏松性骨折的AUC为0.945(95%CI:0.909~0.981),其预测敏感性为95.7%、特异性为90.2%。血清β-CTX、Cathe K、OPG水平联合预测PMO患者发生骨质疏松性骨折的AUC高于血清β-CTX、Cathe K、OPG水平单独(Z分别为2.148、2.581、3.145,P均<0.05)。结论PMO患者血清β-CTX、Cathe K水平明显升高,而血清OPG水平明显降低;血清β-CTX、Cathe K、OPG水平均可作为预测PMO患者发生骨质疏松性骨折的生物学指标,并且三者联合时预测效能更高。

Effects of inhibitors on the protease profiles and degradation of activated Cry toxins in larval midgut juices of Cnaphalocrocis medinalis (Lepidoptera:Pyralidae)

Midgut juice plays an important role in food digestion and detoxification in insects.In order to understand the potential of midgut juice of Cnaphalocrocis medinalis(Guenée)to degrade Bt proteins,the enzymatic activity of midgut juice and its degradation of Bt proteins(Cry2A,Cry1C,Cry1Aa,and Cry1Ac)were evaluated in this study through protease inhibitor treatments.The activities of total protease in midgut juices were significantly inhibited by phenylmethylsulfonyl fluoride(PMSF),tosyl-L-lysine chloromethyl ketone(TLCK),pepstatin A and leupeptin.The enzymatic activity of chymotrypsin was significantly inhibited by PMSF,and enzymatic activity of trypsin was significantly inhibited by ethylenediaminetetraacetic acid(EDTA),PMSF,tosyl phenylalanine chloromethyl ketone(TPCK),TLCK and trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane(E-64).EDTA could significantly inhibit the degradation of Cry2A by C.medinalis.EDTA,PMSF,TPCK,and TLCK could inhibit the degradation of Cry1C and Cry1Aa.EDTA,PMSF,TPCK,TLCK,and E-64 could inhibit the degradation of Cry1Ac.Our results indicated that some protease inhibitors hindered various enzymatic activities in the larval midgut of C.medinalis,which may reduce the insect’s ability to degrade Bt toxins.These findings may aid the application of protease inhibitors in the management of this insect pest in the future.

Safety evaluation and whole genome sequencing for revealing the ability of Penicillium oxalicum WX-209 to safely and effectively degrade citrus segments

The microbial potential of Penicillium has received critical attention.The present research aimed to elucidate the efficacy of crude enzyme secreted from Penicillium oxalicum WX-209 in degrading citrus segments and evaluate the safety of the process.Results showed that citrus segment membranes gradually dissolved after treatment with the crude enzyme solution,indicating good degradation capability.No significant differences in body weight,food ingestion rate,hematology,blood biochemistry,and weight changes of different organs were found between the enzyme intake and control groups.Serial experiments showed that the crude enzyme had high biological safety.Moreover,the whole genome of P.oxalicum WX-209 was sequenced by PacBio and Illumina platforms.Twenty-five scaffolds were assembled to generate 36 Mbp size of genome sequence comprising 11369 predicted genes modeled with a GC content of 48.33%.A total of 592 genes were annotated to encode enzymes related to carbohydrates,and some degradation enzyme genes were identified in strain P.oxalicum WX-209.

The expression of Usp26 gene in mouse testis and brain

Deubiquitinating enzymes （DUBs） play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 （USP26） is a member of this family. The expression of Usp26 in mammalian testis and in other tissues has yet to be fully elucidated. To study the expression of Usp26 mRNA and protein in various murine tissues, reverse transcription （RT）-PCR and immunohistochemistry analyses were carried out. The RT-PCR analysis showed that the Usp26 transcript was expressed in all of the tested tissues. USP26 protein localization was examined by immunohistochemistry, and it was shown that USP26 was not detectable at 20 days postpartum, with the expression restricted to the cytoplasm of condensing spermatids （steps 9-16）, Leydig cells and nerve fibers in the brain. In addition, the USP26 protein was detected at moderate levels in myocardial ceils, the corpus of epidydimis, epithelium of the renal tubules and the seminal gland of postnatal day 35 mice. Its spatial and temporal expression pattern suggests that Usp26 may play an important role in development or function of the testis and brain. Further research into these possibilities is in progress.

a-Synuclein: A fusion chaperone significantly boosting the enzymaticperformance of PET hydrolase

Extensive use of polyethylene terephthalate (PET) has brought about global environmental problems. Arecently reported PET hydrolase (PETase) discovered from Ideonella sakaiensis showed high potentialfor degrading PET at moderate temperatures, but its activity and stability need further improvementfor practical applications. Herein, we proposed to use a-synuclein (aS) as a fusion chaperone and createdsix PETase-aS fusion enzymes with linkers of different types and lengths. All the fusion enzymes exhibited improved enzymatic performance, presenting 1.5 to 2.6-fold higher activity towards bis-2(hydroxyethyl) terephthalate than PETase, as well as significantly increased stabilities. Fluorescencespectroscopy indicated that the chaperone fusion tightened the overall conformation and resulted inthe opening of the substrate binding pocket, which led to the improved thermal stability and catalyticactivity of the fusion enzymes. Remarkably, one of the fusion proteins, PETase-[(GS)(EK)]10-aS, showed3.2 to 5.1 times higher PET degradation capability than PETase. The significantly boosted PET degradationperformance was not only attributed to the enhanced enzymatic activity and stability, but also possiblydue to the binding affinity of the fused aS domain for PET. These findings demonstrated that aS was aneffective fusion chaperone for significantly enhancing the enzymatic performance of PETase.

Manifestation of Pathological States of Numerous Diseases in the Largest Organ of the Human Body: (I) Basics and the Diseases of Tendon

We analyze the crucial biochemical and biophysical properties of the basic constituents—connective tissues (CT), and interstitial fluid (IF) constituting the non-cellular part of the fascia. We provide ample evidence that the resident cells and cells in transit in the fascia are continuously interacting with the non-cellular constituents to form an active organ with well-defined functions. We show evidence that pathological states of diseases of internal organs, as well as that of the constituents of the fascia itself, manifest in certain CTIF domains of the fascia. Numerous diseases originate from imbalance of the digestion and synthesis of the native collagen triple helices. Review on the scanning electron microscopy examination of cross-section of tendons indicates that micro-fibrils of collagen I form regular geometrical structures, supporting the hypothesis that the collagen fibrils assemble like liquid crystals. Information on the age of Achilles tendons has been reported, based on dating of the 14C atoms generated from the nuclear bomb tests in 1955-1963. The causes of spontaneous tendon rupture and tendinopathy are analyzed. Plausible clinical measures to treat tendinopathy are briefly discussed, including the application of synthetic mechano-growth factor, glyceryl trinitrate patch (to supply nitric oxide), platelet rich plasma, proteomic profile analysis and microRNA 29a therapy.

The quantity of OA and activity of cellulase and polygalacturonase are involved in variation of virulence in Sclerotium rolfsii

In order to understand the pathogenic mechanisms of Sclerotium rolfsii on peanut and to analyze the variation of virulence in S.rolfsii strains,the highly virulent strain(ZY2)and weakly virulent strain(GP3-1)were investigated under both in vivo and in vitro conditions.The results indicated that S.rolfsii directly infected peanut by producing infection cushions.ZY2 formed infection cushions earlier than GP3-1,and ZY2 produced a greater number of infection cushions compare to GP3-1.Both strains could utilize cellulose,xylose,or polygalacturonic acid in the Czapek medium.The activities of cellulase(CL)and polygalacturonase(PG)in the inoculated peanut stems increased significantly at 9 h after inoculation.The activities of CL and PG produced by ZY2 in the inoculated stems were significantly higher than that produced by GP3-1.Both strains could produce oxalic acid(OA),and the content of OA produced by ZY2 in the inoculated stems was higher than that produced by GP3-1.In summary,it suggested that S.rolfsii destroyed peanut cells through physical and biochemical factors by secreting a large amount of OA,CL and PG during the formation of infection cushions.The difference in OA content,activity of CL and PG produced by highly and weakly virulent strains played important roles in variation of virulence.