Production and properties of a laccase isozyme (FvLcc3) from the edible mushroom Flammulina velutipes, which is undetectable under the culture condition for fruiting body formation.

Extracellular laccase isozyme (FvLcc3) from the edible mushroom Flammulina velutipes was found to be undetectable under the culture condition for fruiting body formation. FvLcc3 was purified and determined to be an approximately 53-kDa monomeric protein. FvLcc3 showed the highest catalytic efficiency (kcat/Km) toward 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) followed by 2,6-dimethoxyphenol and guaiacol and did not oxidize 3,4-dihydroxy-l-phenylalanine and l-tyrosine.

Relationship between fruiting body development and extracellular laccase production in the edible mushroom Flammulina velutipes.

The biochemical mechanism underlying the development of fruiting bodies in Flammulina velutipes, an edible mushroom, was investigated using the YBLB colorimetric assay to distinguish between the normal strain (FVN-1) and the degenerate strain (FVD-1). In this assay, the color of the YBLB medium (blue-green) inoculated with FVN-1 exhibiting normal fruiting body development changed to yellow, while the color of the medium inoculated with FVD-1 changed to blue. In this study, we found that this color difference originated from extracellular laccase produced by FVN-1. Moreover, FVN-1 exhibited considerably higher extracellular laccase activity than FVD-1, under conditions facilitating fruiting body formation. Overall, these findings suggest that extracellular laccase is involved in the fruiting body development process in F. velutipes.

Biochemical synthesis of the medicinal sugar l-gulose using fungal alditol oxidase.

Some rare sugars can be potently medicinal, such as l-gulose. In this study, we present a novel alditol oxidase (fAldOx) from the soil fungus Penicillium sp. KU-1, and its application for the effective production of l-gulose. To the best of our knowledge, this is the first report of a successful direct conversion of d-sorbitol to l-gulose. We further purified it to homogeneity with a ∼108-fold purification and an overall yield of 3.26%, and also determined the effectors of fAldOx. The enzyme possessed broad substrate specificity for alditols such as erythritol (kcat/KM, 355 m-1 s-1), thus implying that the effective production of multiple rare sugars for medicinal applications may be possible.

Efficient production of the rare sugar l-gulose using a wheat-bran culture extract of Penicillium sp. KU-1.

We found that l-gulose, a rare sugar, was produced from d-sorbitol efficiently, using a wheat-bran culture extract of the fungus Penicillium sp. KU-1 isolated from soil. The culture extract showed enzyme activity for the oxidation of d-sorbitol to produce l-gulose; a high production yield of approximately 94% was achieved.

Heterologous expression of two minor laccase isozyme cDNAs from the edible mushroom Grifola frondosa.

Two cDNAs encoding the minor laccase isozymes (Lac2 and Lac3) of Grifola frondosa were cloned, characterized, and expressed in Pichia pastoris. The recombinant Lac2 (rLac2) was stable at pH 6.0, whereas the recombinant Lac3 (rLac3) was stable in a broad pH range (pH 4.0-8.0). In addition, rLac2 and rLac3 showed the highest catalytic efficiency (kcat/Km) for 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid).

Occurrence of the (2R,3S)-Isomer of 2-Amino-3,4-dihydroxybutanoic Acid in the Mushroom Hypsizygus marmoreus.

Here, we report the occurrence of the (2R,3S)-isomer of 2-amino-3,4-dihydroxybutanoic acid (d-ADHB) in the fruiting body of an edible mushroom, Hypsizygus marmoreus. This is an unusual example of the accumulation of a d-amino acid whose enantiomer is not a proteinogenic amino acid. We show that d-ADHB occurs specifically in the mushroom H. marmoreus. Other edible mushrooms examined, including Pholiota microspora, Pleurotus eryngii, Mycena chlorophos, Sparassis crispa, Grifola frondosa, Pleurotus ostreatus, and Flammulina velutipes, do not contain detectable levels of d-ADHB. The concentration of d-ADHB in the fruiting body of H. marmoreus is relatively high (approximately 1.3 mg/g of fruiting body) and is comparable to the concentration of some of the most abundant free proteinogenic amino acids. Quantitative analysis of d-ADHB during fruiting body development demonstrated that the amino acid is synthesized during the fruiting body formation period. The absence of the putative precursors of d-ADHB, the (2S,3S)-isomer of ADHB and 2-oxo-tetronate, and the enzyme activities of d-ADHB racemase (2-epimerase) and transaminase suggested that d-ADHB is synthesized by a unique mechanism in this organism. Our data also suggested that the lack of or low expression of a d-ADHB degradation enzyme is a key determinant of d-ADHB accumulation in H. marmoreus.

Novel process for producing 6-deoxy monosaccharides from l-fucose by coupling and sequential enzymatic method.

We biosynthesized 6-deoxy-L-talose, 6-deoxy-L-sorbose, 6-deoxy-L-gulose, and 6-deoxy-L-idose, which rarely exist in nature, from L-fucose by coupling and sequential enzymatic reactions. The first product, 6-deoxy-L-talose, was directly produced from L-fucose by the coupling reactions of immobilized D-arabinose isomerase and immobilized L-rhamnose isomerase. In one-pot reactions, the equilibrium ratio of L-fucose, L-fuculose, and 6-deoxy-L-talose was 80:9:11. In contrast, 6-deoxy-L-sorbose, 6-deoxy-L-gulose, and 6-deoxy-L-idose were produced from L-fucose by sequential enzymatic reactions. D-Arabinose isomerase converted L-fucose into L-fuculose with a ratio of 88:12. Purified L-fuculose was further epimerized into 6-deoxy-L-sorbose by D-allulose 3-epimerase with a ratio of 40:60. Finally, purified 6-deoxy-L-sorbose was isomerized into both 6-deoxy-L-gulose with an equilibrium ratio of 40:60 by L-ribose isomerase, and 6-deoxy-L-idose with an equilibrium ratio of 73:27 by D-glucose isomerase. Based on the amount of L-fucose used, the production yields of 6-deoxy-L-talose, 6-deoxy-L-sorbose, 6-deoxy-L-gulose, and 6-deoxy-L-idose were 7.1%, 14%, 2%, and 2.4%, respectively.

Enzymatic production of three 6-deoxy-aldohexoses from L-rhamnose.

6-Deoxy-L-glucose, 6-deoxy-L-altrose, and 6-deoxy-L-allose were produced from L-rhamnose with an immobilized enzyme that was partially purified (IE) and an immobilized Escherichia coli recombinant treated with toluene (TT). 6-Deoxy-L-psicose was produced from L-rhamnose by a combination of L-rhamnose isomerase (TT-PsLRhI) and D-tagatose 3-epimerase (TT-PcDTE). The purified 6-deoxy-L-psicose was isomerized to 6-deoxy-L-altrose and 6-deoxy-L-allose with L-arabinose isomerase (TT-EaLAI) and L-ribose isomerase (TT-AcLRI), respectively, and then was epimerized to L-rhamnulose with immobilized D-tagatose 3-epimerase (IE-PcDTE). Following purification, L-rhamnulose was converted to 6-deoxy-L-glucose with D-arabinose isomerase (TT-BpDAI). The equilibrium ratios of 6-deoxy-L-psicose:6-deoxy-L-altrose, 6-deoxy-L-psicose:6-deoxy-L-allose, and L-rhamnulose:6-deoxy-L-glucose were 60:40, 40:60, and 27:73, respectively. The production yields of 6-deoxy-L-glucose, 6-deoxy-L-altrose, and 6-deoxy-L-allose from L-rhamnose were 5.4, 14.6, and 25.1%, respectively. These results indicate that the aldose isomerases used in this study acted on 6-deoxy aldohexoses.

Skipping Breakfast is Correlated with Obesity.

OBJECTIVE: Despite the fact that the total energy intake of Japanese people has decreased, the percentage of obese people has increased. This suggests that the timing of meals is related to obesity. The purpose of the study was to investigate the relationship between the timing of meals and obesity, based on analyses of physical measurements, serum biochemical markers, nutrient intake, and lifestyle factors in the context of Chrononutrition. PARTICIPANTS AND METHODS: We analyzed data derived from 766 residents of Toon City (286 males and 480 females) aged 30 to 79 years who underwent detailed medical examinations between 2011 and 2013. These medical examinations included. (1) physical measurements (waist circumference, blood pressure, etc.); (2) serum biochemical markers (total cholesterol, etc.); (3) a detailed questionnaire concerning lifestyle factors such as family structure and daily habits (22 issues), exercise and eating habits (28 issues), alcohol intake and smoking habits; (4) a food frequency questionnaire based on food groups (FFQg); and (5) a questionnaire concerning the times at which meals and snacks are consumed. RESULTS: The values for body mass index (BMI) and waist circumference were higher for participants who ate dinner less than three hours before bedtime (<3-h group) than those who ate more than three hours before bedtime (>3-h group). The Chi-square test showed that there was a significant difference in eating habits, e.g., eating snacks, eating snacks at night, having dinner after 8 p.m., and having dinner after 9 p.m., between the <3-h group and the >3-h group. Multiple linear regression analysis showed that skipping breakfast significantly influenced both waist circumference (ß = 5.271) and BMI (ß = 1.440) and that eating dinner <3-h before going to bed only influenced BMI (ß = 0.581). CONCLUSION: Skipping breakfast had a greater influence on both waist circumference and BMI than eating dinner <3-h before going to bed.

Purification and characterization of the extracellular laccase produced by Trametes polyzona WR710-1 under solid-state fermentation.

Laccase from Trametes polyzona WR710-1 was produced under solid-state fermentation using the peel from the Tangerine orange (Citrus reticulata Blanco) as substrate, and purified to homogeneity. This laccase was found to be a monomeric protein with a molecular mass of about 71 kDa estimated by SDS-PAGE. The optimum pH was 2.0 for ABTS, 4.0 for L-DOPA, guaiacol, and catechol, and 5.0 for 2,6-DMP. The K(m) value of the enzyme for the substrate ABTS was 0.15 mM, its corresponding V(max) value was 1.84 mM min(-1), and the k(cat)/K(m) value was about 3960 s(-1) mM(-1). The enzyme activity was stable between pH 6.0 and 8.0, at temperatures of up to 40 °C. The laccase was inhibited by more than 50% in the presence of 20 mM NaCl, by 95% at 5 mM of Fe(2+), and it was completely inhibited by 0.1 mM NaN(3). The N-terminal amino acid sequence of this laccase is AVTPVADLQISNAGISPDTF, which is highly similar to those of laccases from other white-rot basidiomycetes.

Singlet oxygen induced products of linoleates, 10- and 12-(Z,E)-hydroxyoctadecadienoic acids (HODE), can be potential biomarkers for early detection of type 2 diabetes.

Current diagnostic tests such as glycemic indicators have limitations for early detection of impaired glucose tolerance (IGT), which leads to diabetes. Oxidative stress induced by various oxidants in a random and destructive manner is considered to play an important role in the pathophysiology of a number of human disorders and diseases such as impaired glucose tolerance. We have developed an improved method for the measurement of in vivo lipid peroxidation, where the presence of 8-iso-prostaglandin F2α (8-iso-PGF2α), hydroxyoctadecadienoic acids (HODEs), hydroxyeicosatetraenoic acids (HETEs), and 7-hydroxycholesterol (7-OHCh), as well as their parent molecules, linoleic acid (LA) and cholesterol (Ch), was determined by performing LC-MS/MS (for 8-iso-PGF2α, HODE, and HETE) and GC-MS (for 7-OHCh, LA, and Ch) after reduction with triphenyl phosphine and saponification by potassium hydroxide. We then applied this method to volunteers (n = 57), including normal type (n = 43), "high-normal" (fasting plasma glucose, 100-109 mg/dL, n = 7), pre-diabetic type (IGT, n = 5), and diabetic type (n = 2) subjects who are diagnosed by performing oral glucose tolerance tests (OGTTs). Several biomarkers in plasma, such as insulin, leptin, adiponectin, interleukin-6, tumor necrosis factor-α, high sensitivity-C-reactive protein, HbA1c, and glucose levels were measured during OGTT. We found that the fasting levels of (10- and 12-(Z,E)- HODE)/LA increased significantly with increasing levels of HbA1c and glucose during OGTT and with insulin secretion and resistance index. In conclusion, 10- and 12-(Z,E)-HODE may be prominent biomarkers for the early detection of IGT and "high-normal" type without OGTT.

A cross-sectional survey of factors influencing bone mass in junior high school students.

OBJECTIVE: The purpose of this study is to investigate factors influencing the osteo-sono assessment index (OSI) in junior high school students (boys, girls who had reached menarche, and girls who had not). METHODS: A total of 9,743 students (4,974 boys and 4,769 girls) in Ehime Prefecture participated in this study. We measured body mass index (BMI) and calcaneal bone mass using OSI. In parallel, participants answered a questionnaire relating to age, sex, menarche, exercise habits, milk intake, and history of bone fractures during the preceding year. To determine the factors influencing OSI, we calculated an individual standardized partial regression coefficient (ß) using multiple linear regression (MLR) analysis. RESULTS: For boys, MLR showed that BMI (ß = 0.300), age (ß = 0.260), current exercise habits (ß = 0.106), and milk intake per day in primary school (ß = 0.085) statistically significantly influenced OSI. For girls who had reached menarche, BMI (ß = 0.302), current exercise habits (ß = 0.237), age (ß = 0.140), and bone fracture during the preceding year (ß = 0.036) influenced OSI. For girls who had not reached menarche, current exercise habits (ß = 0.242), BMI (ß = 0.135), and age (ß = 0.085) influenced OSI. CONCLUSIONS: There were differences between the factors related to OSI among boys, girls who had reached menarche, and girls who had not. BMI, exercise habits, and age were the common factors related to OSI. Particularly for girls, exercise habits had a great influence on OSI.

Biodegradation of bisphenol A and decolorization of synthetic dyes by laccase from white-rot fungus, Trametes polyzona.

Purified laccase from Trametes polyzona WR710-1 was used as biocatalyst for bisphenol A biodegradation and decolorization of synthetic dyes. Degradation of bisphenol A by laccase with or without redox mediator, 1-hydroxybenzotriazole (HBT) was studied. The quantitative analysis by HPLC showed that bisphenol A rapidly oxidized by laccase with HBT. Bisphenol A was completely removed within 3 h and 4-isopropenylphenol was found as the oxidative degradation product from bisphenol A when identified by GC-MS. All synthetic dyes used in this experiment, Bromophenol Blue, Remazol Brilliant Blue R, Methyl Orange, Relative Black 5, Congo Red, and Acridine Orange were decolorized by Trametes laccase and the percentage of decolorization increased when 2 mM HBT was added in the reaction mixture. This is the first report showing that laccase from T. polyzona is an affective enzyme having high potential for environmental detoxification, bisphenol A degradation and synthetic dye decolorization.

Comparison of regional differences in health indicators and standard mortality ratio for stroke in subjects in ehime prefecture.

OBJECTIVE: The purpose of this study was to investigate regional differences in the standard mortality ratio (SMR) and risk factors (including dietary habits) for stroke across the three regions of Ehime Prefecture - Toyo (east), Chuyo (central), and Nanyo (south). PARTICIPANTS AND METHODS: We obtained medical records derived from 956,979 medical examinations carried out at JA Ehime Kouseiren Medical Examination Centers between April 1994 and March 2006. We analyzed data from 132,090 subjects (Toyo - 47,654, Chuyo - 38,435, Nanyo - 46,001) who underwent their first medical examination during this period. To analyze differences between the three regions, we first calculated the SMR for stroke based on data from the Basic Residential Registers and Health Statistics Bureau. Secondly, we calculated significant differences in body mass index, systolic blood pressure (SBP), diastolic blood pressure (DBP), blood glucose (Glu), and total cholesterol (T-CHO). Thirdly, we used the Chi-square test to calculate significant differences in the percentage of subjects who consumed the following foods on a daily basis: rice, bread, eggs, fish, meat, vegetables, dairy products, and fruit juice. RESULTS: Despite the fact that regional differences in the SMR for stroke have been decreasing, in both men and women in Nanyo, the mean values for SBP and DBP were significantly higher and the mean value for T-CHO was significantly lower than in Toyo and Chuyo. In Nanyo, the percentage of subjects who consumed rice and fish (men and women), meat (men), and juice (women) on a daily basis was higher than in Toyo and Chuyo. CONCLUSION: In Nanyo, higher SMR for stroke may be related to high SBP and DBP and low T-CHO. As background to these results, it is also thought that regional differences in dietary habits may have an influence.

Daily rice intake strongly influences the incidence of metabolic syndrome in Japanese men aged 40-59 years.

OBJECTIVES: The first objective of this study was to classify men aged 40-74 yrs with metabolic syndrome (MetS) according to daily rice intake, and the second was to investigate physical measurements, physiological examinations, blood biochemical assays, intake of food other than rice and lifestyle and environmental factors in the study group. METHODS: We analyzed data from 6095 men aged 40-74 yrs who had undergone full medical examinations. The men were classified into 3 age groups: (1) 40-49 yrs, (2) 50-59 yrs, and (3) 60-74 yrs. The men were classified further into 3 groups according to daily rice intake: group 1 (≤300 g), group 2 (300-450 g), and group 3 (≥450 g). The relationship between daily rice intake and the following factors was analyzed in the three age brackets: (1) physical measurements including waist circumference, (2) physiological measurements, (3) serum biochemical indices, (4) whether or not the person was taking medication for hypertension, diabetes mellitus or serum lipid abnormalities, (5) lifestyle, and (6) consumption of foods other than rice. RESULTS: Daily rice intake was related strongly to the occurrence of MetS in all three age brackets. Multiple logistic regression analysis showed (1) a significant increase in the odds ratio for MetS (1.461 times) for group 3 compared with group 1 in men aged 40-49 yrs and (2) a significant increase in the odds ratio for MetS (1.501 times) for group 3 compared with group 1 in men aged 50-59 yrs. However, there was no significant difference in the odds ratio for MetS among rice intake groups in the 60-74 age bracket. CONCLUSION: In men aged 40-59 yrs, daily rice intake strongly influenced the incidence of MetS, whereas in men aged 60-74 yrs, there was no relationship between daily rice intake and MetS.

Decolorization of synthetic dyes and biodegradation of bisphenol a by laccase from the edible mushroom, Grifola frondosa.

A major laccase isozyme from Grifola frondosa (Lac 1) was found to be effective for decolorizing of synthetic dyes and degrading of bisphenol A. The oxidative capability of Lac 1 toward synthetic dyes and bisphenol A was enhanced in the presence of the redox mediator, 1-hydroxybenzotriazole. The major product from the degradation of bisphenol A by Lac 1 was determined to be 4-isopropenylphenol.

CoPK32 is a novel stress-responsive protein kinase in the mushroom Coprinopsis cinerea.

BACKGROUND: In a previous study, we conducted an expression cloning screen of a cDNA library prepared from Coprinopsis cinerea mycelia using Multi-PK antibodies and detected a wide variety of Ser/Thr protein kinases. One of the isolated clones, CMZ032, was found to encode a putative Ser/Thr protein kinase designated CoPK32. In the present study, we investigated the biochemical properties and physiological significance of CoPK32. METHODS: CoPK32 was expressed in Escherichia coli, and its biochemical properties were examined. The effects of high osmotic stresses on the growth of C. cinerea and on the endogenous CoPK32 activity in mycelia were also examined. RESULTS: CoPK32 showed autophosphorylation activity and effectively phosphorylated exogenous protein substrates. CoPK32S, a splice variant that was 18 amino acids shorter than CoPK32, showed much lower protein kinase activity than CoPK32. The catalytic properties of CoPK32 deletion mutants suggested that the C-terminal region of CoPK32 was important for the kinase activity and recognition of substrates. CoPK32 was highly expressed in the actively growing region of the mycelial colony. When mycelia were stimulated by high osmotic stresses, endogenous CoPK32 was markedly activated and the mycelial growth was severely inhibited. The activation of CoPK32 activity by high osmotic stresses was abrogated by SB202190 or SB239063 as well-known inhibitors of p38 mitogen-activated protein kinase. CONCLUSIONS: CoPK32 is involved in the stress response pathway in mycelia of C. cinerea in response to environmental stresses. GENERAL SIGNIFICANCE: In C. cinerea, protein kinases such as CoPK32 play important roles in signal transduction pathways involved in stress responses.

Extracellular laccase produced by an edible basidiomycetous mushroom, Grifola frondosa: purification and characterization.

A major laccase isozyme (Lac 1) was isolated from the culture fluid of an edible basidiomycetous mushroom, Grifola frondosa. Lac 1 was revealed to be a monomeric protein with a molecular mass of 71 kDa. The N-terminal amino acid sequence of Lac 1 was highly similar to those of laccases of some other white-rot basidiomycetes. Lac 1 showed the typical absorption spectrum of a copper-containing enzyme. The enzyme was stable in a wide pH range (4.0 to 10.0), and lost no activity up to 60 °C for 60 min. The optimal pH of the enzyme activity varied among substrates. The K(m) values of Lac 1 toward 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), 2,6-dimethoxyphenol, guaiacol, catechol, and 3,4-dihydroxy-L-phenylalanine were 0.0137 mM, 0.608 mM, 0.531 mM, 2.51 mM, and 0.149 mM respectively. Lac 1 activity was remarkably inhibited by the chloride ion, in a reversible manner. Lac 1 activity was also inhibited by thiol compounds.

Catalytic properties and crystal structure of quinoprotein aldose sugar dehydrogenase from hyperthermophilic archaeon Pyrobaculum aerophilum.

We identified a gene encoding a soluble quinoprotein glucose dehydrogenase homologue in the hyperthermophilic archaeon Pyrobaculum aerophilum. The gene was overexpressed in Escherichia coli, after which its product was purified and characterized. The enzyme was extremely thermostable, and the activity of the pyrroloquinoline quinone (PQQ)-bound holoenzyme was not lost after incubation at 100 degrees C for 10 min. The crystal structure of the enzyme was determined in both the apoform and as the PQQ-bound holoenzyme. The overall fold of the P. aerophilum enzyme showed significant similarity to that of soluble quinoprotein aldose sugar dehydrogenase (Asd) from E. coli. However, clear topological differences were observed in the two long loops around the PQQ-binding sites of the two enzymes. Structural comparison revealed that the hyperthermostability of the P. aerophilum enzyme is likely attributable to the presence of an extensive aromatic pair network located around a beta-sheet involving N- and C-terminal beta-strands.

Novel Ca2+/calmodulin-dependent protein kinase expressed in actively growing mycelia of the basidiomycetous mushroom Coprinus cinereus.

We isolated cDNA clones for novel protein kinases by expression screening of a cDNA library from the basidiomycetous mushroom Coprinus cinereus. One of the isolated clones was found to encode a calmodulin (CaM)-binding protein consisting of 488 amino acid residues with a predicted molecular weight of 53,906, which we designated CoPK12. The amino acid sequence of the catalytic domain of CoPK12 showed 46% identity with those of rat Ca2+/CaM-dependent protein kinase (CaMK) I and CaMKIV. However, a striking difference between these kinases is that the critical Thr residue in the activating phosphorylation site of CaMKI/IV is replaced by a Glu residue at the identical position in CoPK12. As predicted from its primary sequence, CoPK12 was found to behave like an activated form of CaMKI phosphorylated by an upstream CaMK kinase, indicating that CoPK12 is a unique CaMK with different properties from those of the well-characterized CaMKI, II, and IV. CoPK12 was abundantly expressed in actively growing mycelia and phosphorylated various proteins, including endogenous substrates, in the presence of Ca2+/CaM. Treatment of mycelia of C. cinereus with KN-93, which was found to inhibit CoPK12, resulted in a significant reduction in growth rate of mycelia. These results suggest that CoPK12 is a new type of multifunctional CaMK expressed in C. cinereus, and that it may play an important role in the mycelial growth.