著者

Shinya Fushinobu Masafumi Hidaka Andressa M. Hayashi Takayoshi Wakagi Hirofumi Shoun Motomitsu Kitaoka

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.58, no.3, pp.91-97, 2011 (Released:2011-09-07)

参考文献数

29

被引用文献数

5 9

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Azasugars are known as potent inhibitors of glycoside hydrolases. In this study, we examined the inhibition of Cellvibrio gilvus cellobiose phosphorylase (CBP) by four azasugars (isofagomine, 1-deoxynojirimycin, castanospermine and calystegine B2) and a non-azasugar (glucono-1,5-lactone). Isofagomine strongly inhibited CBP, whereas 1-deoxynojirimycin, castanospermine, and glucono-1,5-lactone exhibited moderate or weak inhibition. Calystegine B2 did not inhibit CBP. Kinetic analysis in the presence of sulfate indicated that it is an extremely weak competitive inhibitor against phosphate. Moreover, crystal structures of CBP complexed with isofagomine or 1-deoxynojirimycin were determined, revealing molecular recognition of the glucosidase inhibitors by the phosphorolytic enzyme. These inhibitors are bound at subsite −1 and form several hydrogen bonds with the protein and anion (phosphate or sulfate). The strong inhibition by isofagomine is probably due to an electrostatic interaction between its endocyclic amino group and phosphate.

著者

Motomitsu Kitaoka

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0012, (Released:2022-12-17)

被引用文献数

3

---

We created a Microsoft Excel file, Enzyme_Kinetics_Calculator, which includes macro programs that automatically calculates kinetic parameters for typical kinetic equations of enzymatic reactions, accompanied by their standard errors, by minimizing the residual sum of squares thereof. The [S]–v plot is automatically drawn with the theoretical lines and, similarly, the 1/[S]-1/v plot in the case of linear theoretical lines. Enzyme_Kinetics_Calculator is available as a supplementary file for this paper (see J. Appl. Glycosci. Web site).

著者

Takatsugu Miyazaki Hidekazu Tanaka Shuntaro Nakamura Hideo Dohra Kazumi Funane

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0013, (Released:2022-12-26)

被引用文献数

2

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Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with α-(1→2)-branches and are generated by Leuconostoc bacteria. DDE was isolated from Microbacterium dextranolyticum (formerly known as Flavobacterium sp. M-73) 40 years ago, although the amino acid sequence of the enzyme has not been determined. Herein, we found a gene for this enzyme based on the partial amino acid sequences from native DDE and characterized the recombinant enzyme. DDE had a signal peptide, a glycoside hydrolase family 65 domain, a carbohydrate-binding module family 35 domain, a domain (D-domain) similar to the C-terminal domain of Arthrobacter globiformis glucodextranase, and a transmembrane region at the C-terminus. Recombinant DDE released glucose from α-(1→2)-branched α-glucans produced by Leuconostoc citreum strains B-1299, S-32, and S-64 and showed weak hydrolytic activity with kojibiose and kojitriose. No activity was detected for commercial dextran and Leuconostoc citreum B-1355 α-glucan, which do not contain α-(1→2)-linkages. The removal of the D-domain decreased the affinity for α-(1→2)-branched α-glucans but not for kojioligosaccharides, suggesting that D-domain plays a role in α-glucan binding. Genes for putative dextranases, oligo-1,6-glucosidase, sugar-binding protein, and permease were present in the vicinity of the DDE gene, and as a result these gene products may be necessary for the use of α-(1→2)-branched glucans. Our findings shed new light on how actinobacteria utilize polysaccharides produced by lactic acid bacteria.

著者

Daichi Ito Emiri Nakano Shuichi Karita Midori Umekawa Khanok Ratanakhanockchai Chakrit Tachaapaikoon

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0001, (Released:2022-04-20)

被引用文献数

3

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Paenibacillus xylaniclasticus strain TW1, a gram-positive facultative anaerobic bacterium, was isolated as a xylanolytic microorganism from the wastes of a pineapple processing factory. A gene encoding one of its xylanolytic enzymes, a β-xylosidase, was cloned and sequenced. Sequence analysis revealed that this β-xylosidase, named PxXyl43A, was composed of a glycoside hydrolase (GH) family 43 subfamily 12 catalytic module and an unknown function module (UM). The full-length PxXyl43A (PxXyl43A) was heterologously expressed in Escherichia coli and purified. Recombinant PxXyl43A exhibited hydrolysis activity against both p-nitrophenyl-β-D xylopyranoside (pNPX) and p-nitrophenyl-α-L-arabinofuranoside at specific activities of 250 mU/mg and 310 mU/mg, respectively. The optimal reaction pH and temperature for pNPX hydrolysis were 7.1 and 54 °C, respectively. At pH 7.0 and 54 °C, the Km and kcat for pNPX were 1.2 mM and 2.8 ± 0.15 s-1, respectively. It was also discovered that the recombinant unknown function module of PxXyl43A (PxXyl43A-UM) could bind to insoluble xylans like birchwood xylan and oat spelt xylan, whereas it did not bind to cellulosic substrates such as ball-milled cellulose, carboxymethyl cellulose or lichenan. The PxXyl43A-UM’s binding constant value Ka for oat spelt xylan was 2.0 × 10-5 M-1. These results suggest that PxXyl43A possesses a novel carbohydrate-binding module, named as CBMx, specific for xylan-containing polysaccharides.

著者

Katsuyuki Sato Takae Nagasawa Takafumi Kasumi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0011, (Released:2021-12-25)

被引用文献数

1

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We previously demonstrated that the organogermanium compound 3-(trihydroxygermyl)propanoic acid (THGP) enhances the enzymatic and alkaline isomerization of an aldose to a ketose through cis-diol complex formation by multiple mechanisms. Its higher affinity for the ketose than the aldose protects the ketose complex from alkaline decomposition. Furthermore, it has been reported that the aldose-ketose alkaline isomerization pathway includes 1,2-enediol. Therefore, we speculated that the complex-forming ability of THGP could also be applied to enediol, a transient intermediate of alkaline isomerization. To test this prediction, we analyzed the initial rates of glucose or lactose isomerization in a region where there was no substantial difference in pH with and without THGP addition. The results showed that THGP enhanced the rate of fructose or lactulose formation per unit time by approximately 2-fold compared to the control. This finding indicated that THGP could form a complex with the transition state of aldose-ketose alkaline isomerization.

著者

Keisuke Kojima Naoki Sunagawa Yoshihisa Yoshimi Theodora Tryfona Masahiro Samejima Paul Dupree Kiyohiko Igarashi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0017, (Released:2022-03-05)

被引用文献数

6

---

Endo-type xylanases are key enzymes in microbial xylanolytic systems, and xylanases belonging to glycoside hydrolase (GH) families 10 or 11 are the major enzymes degrading xylan in nature. These enzymes have typically been characterized using xylan prepared by alkaline extraction, which removes acetyl sidechains from the substrate, and thus the effect of acetyl groups on xylan degradation remains unclear. Here, we compare the ability of GH10 and 11 xylanases, PcXyn10A and PcXyn11B, from the white-rot basidiomycete Phanerochaete chrysosporium to degrade acetylated and deacetylated xylan from various plants. Product quantification revealed that PcXyn10A effectively degraded both acetylated xylan extracted from Arabidopsis thaliana and the deacetylated xylan obtained by alkaline treatment, generating xylooligosaccharides. In contrast, PcXyn11B showed limited activity towards acetyl xylan, but showed significantly increased activity after deacetylation of the xylan. Polysaccharide analysis using carbohydrate gel electrophoresis showed that PcXyn11B generated a broad range of products from native acetylated xylans extracted from birch wood and rice straw, including large residual xylooligosaccharides, while non-acetylated xylan from Japanese cedar was readily degraded into xylooligosaccharides. These results suggest that the degradability of native xylan by GH11 xylanases is highly dependent on the extent of acetyl group substitution. Analysis of 31 fungal genomes in the Carbohydrate- Active enZymes database indicated that the presence of GH11 xylanases is correlated to that of carbohydrate esterase family 1 acetyl xylan esterases (AXEs), while this is not the case for GH10 xylanases. These findings may imply co-evolution of GH11 xylanases and CE1 AXEs.

著者

Shuntaro Machida Katsuichi Saito Mamoru Nishimoto Motomitsu Kitaoka

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0012, (Released:2022-02-25)

被引用文献数

1

---

Lacto-N-biose I (LNB) is supposed to represent the bifidus factor in human milk oligosaccharides, and can be practically produced from sucrose and GlcNAc using four bifidobacterial enzymes, 1,3-β-galactosyl-N-acetylhexosamine phosphorylase, sucrose phosphorylase, UDP-glucose-hexose 1-phosphate uridylyltransferase, and UDP-glucose 4-epimerase, recombinantly produced by Escherichia coli. Here the production of LNB by the same enzymatic method without using genetically modified enzymes to consider the use of LNB for a food ingredient was reported. All four enzymes were produced as the intracellular enzymes of Bifidobacterium strains. The mixture of the crude extracts contained all four enzymes, with other enzymes interfering with the LNB production, namely, phosphoglucomutase, fructose 6-phosphate phosphoketolase, and glycogen phosphorylase. The first two interfering enzymes were selectively inactivated by heat treatment at 47 °C for 1 h in the presence of pancreatin, and glycogen phosphorylase was disabled by hydrolyzing its possible acceptor molecules using glucoamylase. Finally, 91 % of GlcNAc was converted into LNB in the 100-mL reaction mixture containing 300 mM GlcNAc.

著者

杉本 勝之

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.39, no.1, pp.57-64, 1992-03-31 (Released:2010-06-28)

参考文献数

32

被引用文献数

3 3

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Some experimental results on the utilization of starch in starchy food were explained in this paper. Physicochemical properties of Harusame noodles were affected by the characteristics of thestarch used as well as the method of preparation employed. Potato starch was used as the raw material of Boro and Ebi-Senbei (shrimp craker) because of soft and refreshing taste and higher heat expansion power, respectively. The texture of Mochi can be altered, depending upon the processing methods and some additions of waxy corn or tapioca starch. It was found that the addition of potato or tapioca starch could improve the texure of the noodles. The addition of β-amylase or carbohydrate to some kinds of starchy food effectively retarded the rate of starch retrogradation. The addition of about 5% waxy corn starch was able to repress syneresis of Curdlan gel.

著者

Tamami Ida Naoko Crofts Satoko Miura Ryo Matsushima Naoko Fujita

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0015, (Released:2022-03-05)

被引用文献数

1

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Amylopectin, which consists of highly branched glucose polymers, is a major component of starch. Biochemical processes that regulate the elongation of glucose polymers and the generation and removal of glucose branches are essential for determining the properties of starch. Starch synthases (SSs) and branching enzyme (BE) mainly form complexes consisting of SSI, SSIIa and BEIIb during endosperm development. Loss of BEIIb in rice is complemented by BEIIa, but the compensatory effects differ depending on the presence or absence of inactive BEIIb. To better understand these compensatory mechanisms, ss2a be2b (+) double mutant, which possessed truncated inactive SSIIa and inactive BEIIb, were analyzed. Soluble proteins separated by gel filtration chromatography showed that SSIIa and BEIIb proteins in the wild-type exhibited a broad range of elution patterns and only small amounts were detected in high molecular mass fractions. In contrast, most of truncated inactive SSIIa and inactive BEIIb from ss2a be2b (+) were found in high molecular mass fractions, and the SSI-SSIIa-BEIIb trimeric protein complex found in the wild-type was likely absent in ss2a be2b (+). Those SSIIa and BEIIb proteins in high molecular mass fractions in ss2a be2b (+) were also identified by mass spectrometry. Parental ss2a single mutant had negligible amounts of SSIIa suggesting that the truncated inactive SSIIa was recruited to high-molecular mass complexes in the presence of inactive BEIIb in ss2a be2b (+) double mutant. In addition, SSIVb might be involved in the formation of alternative protein complexes with <300 kDa in ss2a be2b (+).

著者

Tomoya Shintani Yuhei Kosuge Hisashi Ashida

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.65, no.3, pp.37-43, 2018-08-20 (Released:2018-08-20)

参考文献数

45

被引用文献数

6 18

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Glucosamine (GlcN) is commonly used as a dietary supplement to promote cartilage health in humans. We previously reported that GlcN could induce autophagy in cultured mammalian cells. Autophagy is known to be involved in the prevention of various diseases and aging. Here, we showed that GlcN extended the lifespan of the nematode Caenorhabditis elegans by inducing autophagy. Autophagy induction by GlcN was demonstrated by western blotting for LGG-1 (an ortholog of mammalian LC3) and by detecting autophagosomal dots in seam cells by fluorescence microscopy. Lifespan assays revealed that GlcN-induced lifespan extension was achieved with at least 5 mM GlcN. A maximum lifespan extension of approximately 30 % was achieved with 20 mM GlcN (p<0.0001). GlcN-induced lifespan extension was not dependent on the longevity genes daf-16 and sir-2.1 but dependent on the autophagy-essential gene atg-18. Therefore, we suggest that oral administration of GlcN could help delay the aging process via autophagy induction.

著者

Suzuki Naoto Isao Hanashiro Naoko Fujita

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0010, (Released:2023-01-14)

被引用文献数

2

---

Starch is comprised of very large α-glucan molecules composed primarily of linear amylose and highly branched amylopectin. Most methods for analyses of starch structure use hydrolytic enzymes to cleave starch. When undegraded, whole starch structures can be analyzed by gel-permeation chromatography (GPC), but this typically yields a single peak each for amylopectin and amylose. The objective of this study was to stably separate amylopectins in whole starch based on their molecular weight using GPC, and to determine the structure of each peak. When alkali-gelatinized whole starch was applied to GPC columns (Toyopearl HW75S×2, HW65S and HW55S), it was separated into three peaks. Iodine staining and chain length distribution analyses of debranched samples showed that peaks were mainly composed of high-molecular weight (MW) amylopectin consisting of many clusters, low-MW amylopectin consisting of a small number of clusters, and amylose.

著者

Rikako Tsukida Makoto Yoshida Satoshi Kaneko

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0009, (Released:2022-12-26)

被引用文献数

3

---

Woody biomass is anticipated to be a resource for a decarbonized society, but the difficulty of isolating woody components is a significant challenge. Brown-rot fungi, a type of wood rotting fungi, decompose hemicellulose particularly efficiently. However, there are few reports on the hemicellulases from brown-rot fungi. An α-L-arabinofuranosidase belonging to glycoside hydrolase family 51 (GH51) from the brown-rot fungus Gloeophyllum trabeum (GtAbf51A) was cloned and characterized in the present study. Analyses of the phylogeny of GH51 enzymes in wood rotting fungi revealed the existence of two groups, intercellular and extracellular enzymes. After deglycosylation, the recombinant GtAbf51A produced by Pichia pastoris appeared on SDS-PAGE as approximately 71,777 daltons, which is the expected molecular weight based on the amino acid sequence of GtAbf51A. Maximum enzyme activity occurred between pH 2.2 and 4.0 and at 50°C, while it was stable between pH 2.2 and 10.0 and up to 40°C. Due to the presence of a signal peptide, GtAbf51A was thought to hydrolyze polysaccharide containing arabinose. However, the hydrolysis rate of arabinosyl linkages in polysaccharides was only 3%–4% for arabinoxylan and 17% for arabinan. GtAbf51A, in contrast, efficiently hydrolyzed arabinoxylooligosaccharides, particularly O-α-L-arabinofuranosyl-(1→3)-O-β-D-xylopyranosyl-(1→4)-β-Dxylopyranose, which is the principal product of GH10 β-xylanase. These data suggest that GtAbf51A cooperates with other xylan-degrading enzymes, such as β-xylanase, to degrade xylan in nature.

著者

Awanthi Mahanama Geegana Gamage Saki Nagamoto Hirosuke Oku Kanefumi Kitahara Teruko Konishi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0004, (Released:2022-11-01)

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Algal sulfated polysaccharides are known to be effective hyaluronidase inhibitors. We evaluated hyaluronidase inhibitory activity of sulfated polysaccharide (SP) from Caulerpa lentillifera. Results showed that SP with IC50 of 163 μg/mL appears to allosterically inhibit the hyaluronidase activity. Main sugar composition and sulfate content of SP was estimated to be Gal, Glc, Xyl, Man, uronic acids and sulfate in the weight percent of 27.7: 28.9: 14.6: 22.5: 3.4: 21.7. We modified the SP by desulfation and partial hydrolysis with trifluoroacetic acid (TFA) to investigate the effect of sulfate content and molecular weight on inhibition. Hyaluronidase inhibitory activity of desulfated SP, 0.1 M TFA-hydrolyzed SP and 0.5 M TFA-hydrolyzed SP were significantly lower than that of native SP, revealing that sulfate content or molecular weight is important for hyaluronidase inhibition.

著者

松永 幸太郎 竹田 靖史 川崎 貞道

出版者

The Japanese Society of Applied Glycoscience

雑誌

応用糖質科学 (ISSN:13403494)

巻号頁・発行日

vol.45, no.3, pp.239-246, 1998-08-31 (Released:2010-06-28)

参考文献数

26

被引用文献数

2

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澱粉と小麦タンパク質を混合したミックス粉を用いて,澱粉の種類とフライ特性,食感との関係を調べた.結果は次のようにまとめることができる. 1)衣の水分飛散率と破断強度(y=0.96)や食感のサクサク感(r=0.92),硬さ(r=0.97)とは明らかな正の相関性があり,水分飛散率が高い澱粉ほど食感がよく,サクサク感があり,揚がりが良いことがわかった. 2)天ぷらの衣の揚がりの良さは生地に用いる澱粉の種類によって異なり,トウモロコシが最もよく,馬鈴薯と小麦は中程度で,タピオカ,モチトウモロコシは劣った.3)揚がりの最:も良かったトウモロコシ澱粉では,衣の中で澱粉粒の形状が保たれていること,一方揚がりの悪いモチトウモロコシ,タピオカの澱粉では粒の形状が完全に消失しているこどが観察された.

著者

Akane Matsumoto Kanae Nakai Kiyoshi Kawai

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0014, (Released:2022-02-08)

被引用文献数

1

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The soft texture of the pizza crust rim is generated by baking at a high temperature for a short period in a stone oven. In the case of baking in an electric oven, the pizza dough is baked at a much lower temperature and for a longer period, resulting in a harder texture. To improve the texture of electric oven-baked pizza crust, the effects of water and gelatinized starch on the viscoelasticity of pizza dough and the texture of pizza crust was investigated. Rheological properties (storage modulus, loss modulus, and yield stress) of pizza dough decreased with an increase in water content. When wheat flour in the dough was partially replaced with pre-gelatinized wheat starch, the rheological properties of the dough were maintained even at a high-water content. These results indicate that water-enriched dough can be prepared with gelatinized starch and baked using an electric oven. There was no significant difference in apparent density between the conventional and modified pizza crusts. Water content of the crumb part of the modified crust was significantly higher than that of the conventional crust. Texture analysis revealed that the modified pizza crust showed significantly lower stress at high strain than the conventional crust. In addition, sensory evaluation showed that the modified pizza crust exhibited greater firmness and stickiness than the conventional crust, which was attributed to the increased water content with gelatinized starch of the dough.

著者

Ikuko Kakizaki Yoji Kato

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0016, (Released:2022-03-18)

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Over the past 10 years, many products utilizing the functionality of salmon cartilage proteoglycan have come on the market, and consumer awareness of proteoglycan has increased. During this period, the biggest issue has been how to evaluate the amount and quality of proteoglycan in the cartilage extract blended in the products. In this study, we propose an immunological method that can easily evaluate the amount and quality of proteoglycan in the proteoglycan-containing compositions. By the present method, it is possible to evaluate not only the retention of the functional domains of the core protein of proteoglycan, but also that of chondroitin sulfate chains linked to the core protein. Furthermore, the binding activity of proteoglycan to hyaluronan can be evaluated if hyaluronan is used as a probe instead of an antibody. This method is expected to be useful for proteoglycan quality evaluation during the manufacturing process and product storage.

著者

松田 和雄 秦 敬子

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.32, no.2, pp.118-127, 1985-06-30 (Released:2010-03-16)

参考文献数

29

被引用文献数

2 2

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The size and the shape of shellfish glycogen varied with the extraction procedure. The particles of glycogen prepared by extraction with dimethyl sulfoxide (DMSO) were relatively large (20-180nm, diam.) and showed rosette-like structure. The particles of glycogen prepared by trichloroacetic acid (TCA) extraction and the commercial glycogen were much smaller in size (10-130nm and 10-40nm, respectively) and did not show rosette-like structure. The general properties of these glycogen preparations were not significantly different from each other, except that the latter two preparations were more susceptible to pullulanase.The size of the glycogen particles was decreased by treatment with TCA, phosphotungstic acid or 30% potassium hydroxide, but was not changed by treatment with 0.1M or 0.5M sodium hydroxide. Treatment with 2-mercaptoethanol did not disrupt large glycogen particles. Protease and β-amylase did not affect the size of glycogen particles. Large glycogen particles were partially split by treatment with α-amylase, suggesting that a large glycogen particle is composed of fundamental particles (20-30nm, diam.) linked through α-1, 4-glucan chains. On the basis of the foregoing results, a model of glycogen particle was proposed. The relation of the biosynthesis mechanism and the particle formation of glycogen was also discussed mainly from the viewpoint of the role of branching enzyme.

著者

安部 淳一

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.36, no.1, pp.51-57, 1989-03-31 (Released:2010-06-28)

参考文献数

20

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(1) One form and three forms (GI, GII, and GIII) of glucoamylases were purified from crude commercial preparation of Aspergillus niger and Rhizopus delemar, respectively, to be homogenous on disc- and SDS-gel electrophoresis and free from a-amylase and phosphatase. Neither purified glucoamylase from A. niger nor R. delemar could completely hydrolyze various kinds of starches because of the presence of phosphate esters attached to C-3 or C-6 of glucosyl residue, and left a limit-dextrin of large-molecular weight. The concomitant actions of a-amylase and phosphatase with the glucoamylases were found to be necessary for complete hydrolysis of these starches. (2) R. delemar GIII was suggested to have a specific affinity site, "starch-binding site, " for high-molecular-weight substrates from the results of kinetic study and modification with chymotrypsin. GI and GII were suggested to be derived from GIII by the post-secretional modification. (3) Aspergillus sp. K-27 produced the enzyme (s) which degraded well the raw starches. Glucoamylase and a-amylase were separated and purified from the culture filtrate of the fungus. The former seemed to have the "starch-binding site, " based on the results of partial proteolysis and kinetic studies. The latter showed low activity on raw starches but synergistically enhanced the degradation of starch granules with glucoamylase. The removal of the starch-binding site from glucoamylase reduced the ability of raw-starch degradation and abolished the synergistic effect with a-amylase. These results suggested that the starch-binding site plays an importantrole in raw-starch hydrolysis.

著者

永島 伸浩

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.39, no.1, pp.23-40, 1992-03-31 (Released:2010-06-28)

参考文献数

28

被引用文献数

1 1

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The physical characteristics after aging of Mochi prepared by several methods were studied, and the following results were obtained:. 1) Mochi prepared by stamping exhibited much of the initial rice grain structure, while that prepared by a power mixer was of a well-mashed paste form rather than rice grain tissue. 2) The hardness of each type of Mochi measured by a rheolometer depended on the storage conditions : Mochi prepared by a mixer was softer than by stamping with no storage, while that prepared by a mixer was harder than by stamping after storing for 3 hr at 5°C. 3) The creep curves of Mochi measured by a rheoner could be explained by a six-element mechanical model consisting of Hookean body, two pairs of Voigt bodies and a Newtonean body. The shift factor-1/T relationship for Mochi stored at °C resulted in two straight lines, a refraction point being observed at 50°C ; however, no such phenomenon was observed for Mochi stored at-20°C. 4) The cooking loss of Mochi stored at 5°C decreased with increasing storage time, while that of the Mochi stored at -20°C hardly changed . Mochi prepared by stamping showed a small cooking loss after storage at 5 and -20°C, respectively. 5) The crystalline structure of raw glutinous rice could be classified as a type-A pattern, although this pattern disappeared upon heating and was transformed into a type-B pattern after storing at 5°C for one week. In the case of Mochi stored at -20°C, the crystallinity was never recovered. 6) The viscosity of Mochi measured by a Brabender viscograph after storing at 5°C showed a maximum value of 800 to 1000 B. U., while that stored at -20°C showed a maximum value of 200 to 300 B. U. The viscosity of the latter reached a peak after storing for 72 hr, and then decreased with a further period of storage.

著者

小林 武一 井上 真智子 田辺 幾之助 大西 博 福井 作蔵

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.25, no.3, pp.186-192, 1978-09-30 (Released:2010-06-28)

参考文献数

25

被引用文献数

1

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Chl.vulgarisA1-1y-3(11)をそれぞれ20℃,30℃,40℃ で他養培養し,性質の異なる澱粉を得ることを試みた。得られた澱粉は下記のような特性を示した. 1)クロレラ澱粉の結晶形は培養温度の影響を受けず,いずれもA図形であった. 2)アミロース含量は20℃ 培養で得られた澱粉がわずかに高い. 3)低い培養温度で得られた澱粉ほど低温で膨潤がはじまり,かつ膨潤度が大きく,培養温度の影響が顕著である. 4)20℃ 培養で得られた澱粉は他の培養温度のものに比べて著しく総リン量が多い. 5)クロレラ澱粉は微小(0.5~2μm)で,その形も他の澱粉と異なっているが,それらに対する培養温度の影響は認められなかった. 6)X線回折図,形態観察,アミロース含量などから見るかぎり,細胞内澱粉粒と細胞外澱粉粒との間にほとんど差がなかった.なお,本報告の概要は昭和51年度日本澱粉学会大会で発表した.