Effect of 1 064-nm Q-switched Nd:YAG laser on cell viability, protease activity and structures of Malassezia furfur / 中华皮肤科杂志

Objective:To investigate the effect of 1 064-nm Q-switched Nd:YAG laser at different energy settings on cell viability, protease activity and structures of Malassezia furfur. Methods:Cultured standard strains of Malassezia furfur were divided into several groups to be irradiated with 1 064-nm Q-switched Nd:YAG laser at different energies of 0 (control group) , 500, 600, 700, 800 and 900 mJ, respectively. Then, fungal suspensions in the above groups were inoculated onto the Leeming & Notman medium separately. After 7-day culture, the diameter and number of colonies were measured to evaluate the fungal cell viability, the protease activity was measured by using the whole-milk plate medium, and the ultrastructure of Malassezia furfur in each group was observed by transmission electron microscopy. One-way analysis of variance was used for comparisons among multiple groups, least significant difference- t test for multiple comparisons, and Pearson correlation analysis for analyzing correlations of laser energy with colony diameter, number and protease activity. Results:The colony diameter and number both significantly differed among the control group, 500-, 600-, 700-, 800- and 900-mJ groups (colony diameter: 4.05 ± 0.69, 3.76 ± 0.51, 3.28 ± 0.41, 3.09 ± 0.72, 2.54 ± 0.64 and 2.43 ± 0.41 mm, respectively; colony number: 4 787 ± 597, 4 287 ± 761, 1 879 ± 275, 1 082 ± 248 and 209 ± 42, 72 ± 31 colony-forming units, respectively; F = 14.83, 231.85, respectively, both P < 0.05) , and were significantly decreased in the 600-, 700-, 800- and 900-mJ groups compared with the control group (all P < 0.05) . The laser energy was negatively correlated with the colony diameter and number ( r = -0.67, -0.91, respectively, both P < 0.05) . The protease activity significantly differed among the control group, 500-, 700- and 900-mJ groups ( F = 346.60, P < 0.05) , and was significantly lower in the 700- and 900-mJ groups than in the control group (both P < 0.05) . There was a negative correlation between the laser energy and protease activity ( r = -0.94, P < 0.05) . Transmission electron microscopy showed intact fungal structures in the control group, relatively intact fungal structures in the 500-mJ group, and obviously damaged fungal structures in the 600- to 900-mJ groups, and the greater the laser energy, the more severely the fungal structures were damaged. Conclusion:The 1 064-nm Q-switched Nd:YAG laser could affect the cell viability of and protease activity in Malassezia furfur, and damage its structures.

Improved protease activity of Pixian broad bean paste with cocultivation of Aspergillus oryzae QM-6 and Aspergillus niger QH-3

BACKGROUND: The preparation of broad bean koji is a key process in the production of Pixian broad bean paste (PBP). Protease is essential for the degradation of proteins during PBP fermentation. To obtain broad bean koji with high protease activity using the cocultivated strains of Aspergillus oryzae QM-6 (A. oryzae QM-6) and Aspergillus niger QH-3 (A. niger QH-3), the optimization of acid and neutral protease activities was carried out using Box­Behnken design with response surface methodology (RSM). RESULTS: The optimum conditions were found to be as follows: inoculation proportion (X1), 3:1 (A. oryzae QM-6: A. niger QH-3, w/w); culture temperature (X2), 33°C; inoculum size (X3), 0.5% (w/w); incubation time (X4), 5 d. The acid and neutral protease activities were 605.2 ± 12.4 U/g and 1582.9 ± 23.7 U/g, respectively, which were in good agreement with the predicted values. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the broad bean koji extracellular proteins in the case of cocultivation were richer compared to those in the case of A. oryzae QM-6 or A. niger QH-3 strain only. In addition, the free amino acids (FAAs) in the fermentation product were 55% higher in the cocultivation process than in that involving only A. oryzae QM-6, further confirming the diversity of proteases in the fermentation products. CONCLUSIONS: The optimal conditions of koji-making in PBP were obtained using RSM. The cocultivation of A. oryzae and A. niger increases the overall enzyme activities in the culture medium and the FAAs content, which would thus have potential application in the PBP industry.

Correlation between Pr1 protease activity, Pr1 gene expression and strain virulence of Isaria fumosorosea / 生物工程学报

Serine elastic chymotrypsin Pr1 is an enzyme that efficiently degrades insect body wall protein through its connection with the virulence of entomogenous fungi. Therefore, it is important to explore the relationship between the Pr1 protease activity, the Pr1 gene expression and the virulence of different strains of entomogenous fungi. Specific peptide substrate Suc-Ala-Ala-Pro-Phe-pNA and fluorogenic quantitative PCR were used for detecting Pr1 protease activity and Pr1 gene expression, and the slope spray method was used for evaluating the virulence of the fungi on the Myzus persicae. The results indicated that the linear regression equation of the Pr1 protease activity and the virulence of different strains were: y=3.64x+0.62, R²=0.432. It was shown that there is a positive correlation between the Pr1 protease activity and virulence of different strains. Moreover, the result of the multiple linear regression analysis between Pr1 protease activity, Pr1 gene expression and the virulence of different strains was: y=0.236+10.833x₁-0.039x₂ (x₁ represents Pr1 protease activity while x₂ represents Pr1 gene expression), R²=0.568, which suggested that the raw data could be represented by a linear fitting equation. The serial correlation coefficient was high (D-W was 2.444), indicating that Pr1 protease activity and Pr1 gene expression have great effect on the virulence of the fungi. Additionally, VIF=12.705, which shows that moderate multiple collinear exists between Pr1 protease activity and Pr1 gene expression. Therefore, Pr1 protease activity and Pr1 gene expression could be recommended as important indicators for strain virulence selection.

Correlation of prostate-specific antigen with the progression and metastasis of human prostate cancer / 中华男科学杂志

Prostate-specific antigen (PSA) is a biomarker for the diagnosis and management of prostate cancer and involved in the development of prostate cancer and/or its progression from the localized to the metastatic stage. This review presents an overview of the roles of PSA in promoting the progression and metastasis of human prostate cancer and its underlying mechanisms, including its serine protease activity, interaction with the cellular membrane receptor, and suppression of specific immune responsiveness, and also points out some of the key problems to be solved.

Free and attached cells of Bacillus subtilis as starters for production of a soup flavouring (“ogiri egusi”)

Aims: This Bacillus subtilis has been identified to be the main fermenting bacterium during indigenous production of “ogiri egusi”; a traditional soup flavouring rich in protein. Evaluation of the use of starter and broth cultures of this bacterium in the production of ‘ogiri egusi’ was therefore undertaken with the view to improve the fermentation process and quality of product. Methodology and Results: Cowpea granules in association with Bacillus subtilis cells were developed as starter cultures for the fermentation. Results obtained showed that the starter cultures resulted in an increase in the aminonitrogen from 1.67±0.02 to 19.96±0.05 mg N/100 g dry matter in 48 h while the broth cultures increased the aminonitrogen from 1.63±0.03 to 16.54±0.05 mg N/100 g dry matter in 72 h. There was also a corresponding increase in the protease activity of the fermentation conducted with the starter cultures from 2.69±0.03 to 54.98±0.04 mg N/min in 48 h. The broth cultures produced an increase from 2.65±0.02 to 47.61±0.06 mg N/min in 72 h. Changes in these parameters for the natural process were gradual and reached their peaks at 120 h with values of 9.89±0.13 mg N/100g dry matter and 31.92±0.03 mg N/min respectively. Peroxide values for the fermentation processes increased throughout the period; however the starter cultures produced the lowest value (10.20±0.10 meq/kg) showing that rancidity may not occur in the product fermented by the starter culture. Conclusion, significance and impact of study: The starter cultures significantly reduced fermentation time from 96 – 120 h in the natural process to 48 h. Thus use of starter cultures optimized the process of fermentation and will eliminate chances of contamination of product with pathogens and spoilage organisms. This ultimately will improve product quality.

Effect of leather industry effluents on soil microbial and protease activity.

Release of leather industry effluents into the agricultural fields causes indicative changes in nutrient cycling and organic matter processing. In the present study, leather industry effluent discharged soil (test) and undischarged soil (control) were collected from the surrounding areas of industry. The physico-chemical, biological properties and soil protease activity were examined. The study reflected the average mean value of pH, electrical conductivity and water holding capacity of the test soil was found to be 7.94, 0.89 =Mhos cm-1 and 0.51 ml g-1, respectively. In chemical parameters, organic matter, total nitrogen, phosphorus and potassium has the mean of 6.73%, 0.23 g kg-1, 4.28 mg g-1 and 28 =g g-1, respectively. In all the respects, the test soil showed higher values than the control. The soil protease enzyme activity was determined by using substrate casein and the activity was found to be higher (180 =g TE g-1 24 hr-1) in test soil than the control soil (63 =g TE g-1 24 hr-1).

Partial characterization of proteolytic activity in Giardia duodenalis purified proteins

This report describes a preliminary characterization of proteolytic activity of proteins isolated from lysate of Giardia trophozoites of an axenic Brazilian strain. Fractions obtained by high-performance liquid chromatography (FPLC) were tested in SDS-polyacrylamide gel for the protein profiles, and the proteases activity was analyzed using gelatin impregnated SDS-PAGE. The proteases characterization was based on inhibition assays employing synthetic inhibitors for cysteine (E-64, IAA), serine (PMSF, TPCK, TLCK, and elastatinal), metalo (EDTA) and aspartic (pepstatin) proteases. Among thirty eluted fractions, polypeptide bands were observed in eight of them, however, proteolytic activity was detected in four ones (F23, F24, F25 and F26). Protein profiles of these fractions showed a banding pattern composed by few bands distributed in the migration region of 45 to < 18 kDa. The zymograms revealed proteolytic activity in all the four fractions assayed, mainly distributed in the migration region of 62 to 35 kDa. Among the profiles, the main pronounced zones of proteolysis were distinguished at 62, 55, 53, 50, 46 and 40 kDa. In inhibition assays, the protease activities were significantly inhibited by cysteine (E-64) and serine proteases (TPCK, TLCK and elastatinal) inhibitors. Gels incubated with other cysteine and serine protease inhibitors, IAA and PMSF, respectively, showed a decrease in the intensity of hydrolysis zones. Indeed, in the assays with the inhibitors EDTA for metalloproteases and pepstatin for aspartic proteases, none inhibition was detected against the substrate. These observations are relevants, especially if we consider that to define the real role of the proteases in host-parasite interaction, the purification of these enzymes for detailed studies may be warranted.

O presente estudo consiste em uma caracterização preliminar da atividade proteolítica de frações de proteínas purificadas a partir de lisados de trofozoítos de cepa isolada e axenizada no Brasil. Frações obtidas por cromatografia líquida (FPLC) foram analisadas quanto ao perfil eletroforético em géis de poliacrilamida (SDS-PAGE) e a atividade proteolítica foi avaliada em géis contendo gelatina como substrato. A caracterização das enzimas foi realizada a partir da análise do efeito de inibidores sintéticos de cisteína-proteases (E-64, IAA), serina-proteases (PMSF), serina e cisteína-proteases (TPCK, TLCK, elastatinal), metalo-proteases (EDTA) e aspartil proteases (pepstatina) sobre a degradação do substrato. Entre 30 frações eluídas, bandas de proteínas foram observadas em oito delas, entretanto, atividade proteolítica foi detectada apenas nas frações 23, 24, 25 e 26. O perfil eletroforético das proteínas revelou poucas bandas distribuídas na faixa de 45 a 18 kDa. Os zimogramas revelaram zonas de proteólise na faixa de aproximadamente 62 a 35 kDa, entretanto destacaram-se as bandas de hidrólise de 62, 55, 53, 50, 46 e 40 kDa. Nos ensaios de inibição, a proteólise foi marcantemente inibida por E-64, TPCK, TLCK e elastatinal. Redução discreta da proteólise foi observada com IAA e PMSF, enquanto que EDTA e pepstatina não promoveram alteração dos perfis de hidrólise. Estas observações são relevantes, especialmente se considerarmos que para elucidar o envolvimento das proteases na relação parasita-hospedeiro, a purificação dessas moléculas é um requisito importante.

Characterization of HC58cDNA, a putative cysteine protease from the parasite Haemonchus contortus

Because of the complexity of the cathepsin B-like (CBL) family, an information on the biological and biochemical characteristics of individual CBL genes is lacking. In this study, we investigated the degradative effects of the recombinant HC58 protein isolated from Haemonchus contortus parasites on protein substrates over a broad pH range in vitro. This protein, which hydrolyzed the synthetic peptide substrates Z-FR-AMC and Z-RR-AMC, had characteristics of the cysteine protease class of proteins. In the acidic pH range, the isolated protein actively degraded hemoglobin (Hb), the heavy chain of goat immunoglobulin G, and azocasein. By contrast, it degraded fibrinogen in the alkaline pH range. These activities were strongly inhibited in the presence of the cysteine protease inhibitor E-64. While the protein digested Hb, it did not induce the agglutination of erythrocytes from its natural host. These results suggest that the HC58 protein may play a role in the nutrition of this parasite.

Effects of Some Amino Acids on Ammonia Secretion and Extracellular Protease Activity by Three Oomycetes in Synthetic Medium with or without Glucose

The effects of different concentrations of three amino acids as carbon and or nitrogen sources on mycelial dry weights, changes in pH values of synthetic medium, ammonia secretion and extracellular protease activity by three zoosporic fungi, pathogens of fish and shellfish, were studied. As compared with the control, the addition of isoleucine and aspartic acid as nitrogen sources were generally stimulative for mycelial dry weight production whereas phenylalanine was inhibitory irrespective to the tested fungal species. When amino acids served as carbon and nitrogen sources, the mycelial dry weights of the three fungi were increased (mostly non-significantly) relative to untreated control but weights were decreased as the concentrations of the three amino acids raised. The addition of individual amino acids as carbon and nitrogen sources to the medium significantly increased pH values of the medium comparable to the control. The addition of each of the three amino acids as carbon and nitrogen sources to the medium significantly induced ammonia secretion by the three species of zoosporic fungi. Ammonia secretion in synthetic medium amended with amino acids as nitrogen source raised by the three zoosporic fungi relative to untreated control except in case of Achlya racemosa treated with isoleucine. Extracellular protease activity was almost promoted in case of Achlya proliferoides and Saprolegnia furcata cultures treated with isoleucine and aspartic acid individually in presence of glucose and vice versa in case of phenylalanine. However, extracellular protease activity of A. racemosa decreased compared with the control at various concentrations of isoleucine and both phenylalanine and aspartic acid assumed inconsistent effects. Extracellular protease activity of the three zoosporic fungi in the medium devoid of glucose varied depending upon zoosporic fungal species, the tested amino acid and the applied concentrations. The values of protease activity were approximately less two folds than that obtained in presence of glucose.

Intactness of zona pellucida does not affect the secretion of a trypsin-like protease from mouse blastocyst

Assisted hatching (AH), which is known to improve the hatching potential of mammalian embryos, has been used to increase the pregnancy rate in in vitro fertilization cycles. However, the effect of AH on a trypsin-like protease, which is known to be associated with the hatching process, has not been studied. In this study, we evaluate whether the intactness of zona pellucida affects the secretion of a trypsin-like protease from mouse blastocyst. Four- to 8-cell stage mouse embryos were collected at 66- to 68 hr after hCG injection and divided into 3 groups according to the manipulation of zona pellucida. The groups are no treatment (control), drilling of zona pellucida (ZD) and thinning of zona pellucida (ZT). The activity of a trypsin-like protease, blastocyst development and hatching rate were compared among the three groups at 110 and 135 hr after hCG injection, respectively. The protease activity and blastocyst development were not significantly different among control, ZD and ZT groups at 110 and 135 hr after hCG injection, respectively. However, the hatching rate of ZD and ZT groups was significantly higher than that of control group at each time, respectively (p>0.001). Even in the zona pellucida removed embryos, the protease activity did not differ from the control group. In conclusion, the secretion of a trypsin-like protease from mouse blastocyst does not seem to be affected by the intactness of zona pellucida.