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61.
αsl-Casein can be made either soluble or insoluble by adjusting the concentration of coexisting calcium ions. In this study, we tried to make a soluble-insoluble interconvertible enzyme through the formation of a conjugate of an enzyme and αsl-casein using a heterobifunctional crosslinking reagent, N-succinimidyl 3-(2-pyridyldithio)propionate. The conjugate of phosphoglyceromutase and native αs1-casein did not exhibit sufficient calcium-dependent precipitation. However, conjugates of enzymes (phosphoglyceromutase, enolase or peroxidase) and αsl-casein polymerized by transglutaminase precipitated almost completely in the presence of more than 50 mM CaCl2. Most of the enzyme conjugates precipitated as calcium caseinates could be solubilized reversibly with EDTA, without a significant loss of activity. A mixture of the enzyme ? polymerized αs1-casein conjugates prepared with phosphoglyceromutase, enolase and pyruvate kinase could catalyze sequential reactions which convert d-3-phosphoglycerate into pyruvate with the same efficiency as a mixture of free enzymes. These results indicate that conjugates of enzymes and polymerized αs1-casein can be useful as soluble-insoluble interconvertible enzymes. 相似文献
62.
Susumu Ikegami Yutaka Hirose Yuji Kamiya Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(13):2453-2457
Partial acid hydrolysis of asterosaponin A, a steroidal saponin, afforded two new disaccharides in addition to O-(6-deoxy-α-d-glucopyranosyl)-(l→4)-6-deoxy-d-glucose which has been characterized in the preceding paper. The formers were demonstrated as O-(6-deoxy-α-d-galactopyranosyl)-(1→4)-6-deoxy-d-glucose and O-(6-deoxy-α-d-galactopyranosyl)-(l→4)-6-deoxy-d-galactose, respectively.Accordingly, the structure of carbohydrate moiety being composed of two moles each of 6-deoxy-d-galactose and 6-deoxy-d-glucose, was established as O-(6-deoxy-α-d-galactopyranosyl)-(l→4)-O-(6-deoxy-α-d-galactopyranosyl)-(l→4)-O-(6-deoxy-α-d-glucopyranosyl)-(l→4)-6-deoxy-d-glucose, which is attached to the steroidal aglycone through an O-acetal glycosidic linkage. 相似文献
63.
Shintaro Kamiya Fukuko Konishi Sachiko Esaki 《Bioscience, biotechnology, and biochemistry》2013,77(10):1785-1790
Naringenin-7-β-kojibioside, -7-β-sophoroside, -7-[α-d-galactosyl(l→2)β-d-glucoside], -7-[β-d-glucosyl(l→2)β-d-galactoside], and also hesperetin-7-β-kojibioside and -7-β-sophoroside were prepared by the coupling of naringenin or hesperetin with the α-acetobromo derivatives of the appropriate disaccharides, followed by saponification.Their relative bitterness values were discussed in comparison with naringin and neo-hesperidin. 相似文献
64.
Masao Nishiura Sachiko Esaki Shintaro Kamiya 《Bioscience, biotechnology, and biochemistry》2013,77(8):1109-1118
The occurence and distribution of flavonoid glycosides in young leaves and young and mature fruits of many citrus species and trifoliate orange were investigated. The occurence of neohesperidin in both young leaves and young fruits is fairly common to a number of species in subgenus Archicitrus. Ripe fruits of citrus could be classified into (a) the hesperidin group (b) the neohesperidin group (c) the naringin group and (d) the isonaringin group. A new flavanone glycoside, isonaringin, isolated from young fruits of Jagatarayu and Teng mikan is slightly bitter and has been determined by chemical and spectral evidences to have the structure of naringenin-7-rhamnoglucoside. Data showing the occurence of flavanone glycosides in some artificial citrus hybrids were also given. 相似文献
65.
66.
Kentaro Kumoi Tadashi Satoh Kazuyoshi Murata Takeshi Hiromoto Tsunehiro Mizushima Yukiko Kamiya Masanori Noda Susumu Uchiyama Hirokazu Yagi Koichi Kato 《PloS one》2013,8(3)
Assembly of the eukaryotic 20S proteasome is an ordered process involving several proteins operating as proteasome assembly factors including PAC1-PAC2 but archaeal 20S proteasome subunits can spontaneously assemble into an active cylindrical architecture. Recent bioinformatic analysis identified archaeal PAC1-PAC2 homologs PbaA and PbaB. However, it remains unclear whether such assembly factor-like proteins play an indispensable role in orchestration of proteasome subunits in archaea. We revealed that PbaB forms a homotetramer and exerts a dual function as an ATP-independent proteasome activator and a molecular chaperone through its tentacle-like C-terminal segments. Our findings provide insights into molecular evolution relationships between proteasome activators and assembly factors. 相似文献
67.
Robin J. Smith Renate Matzke‐Karasz Takahiro Kamiya Patrick De Deckker 《Acta zoologica》2016,97(1):1-17
Length measurements of sperms of 51 species of Cypridoidea ostracods were taken to supplement the paucity of ostracod sperm data in the published literature. The lengths of the posterior regions (carrying the mitochondria) and the thinner anterior regions were also measured when appropriate. Maximum lengths of sperms for individual species varied from 268 μm for Fabaeformiscandona velifera Smith and Janz, 2008 through to 11 787 μm for Australocypris robusta De Deckker, 1974; these lengths represent the shortest so far recorded for the superfamily and the longest ever recorded in ostracods, respectively. There appears to be only a loose relationship between taxonomy and sperm lengths. Species of the subfamily Candoninae generally have the shortest sperms compared with other subfamilies, but one Candoninae species, Candona altoides Petkovski, 1961, has sperms longer than some species of the families Cyprididae, Ilyocyprididae and Notodromadidae. The family Cyprididae showed the most variation, with sperms ranging from 1000 μm through to 11 787 μm in length. No hypothesis satisfactorily explains the origin of giant sperms in ostracods or the longevity of this trait through geological eras, and their existence remains enigmatic. 相似文献
68.
Background and aim
Recycled sources of phosphorus (P), such as struvite extracted from wastewater, have potential to substitute for more soluble manufactured fertilisers and help reduce the long-term threat to food security from dwindling finite reserves of phosphate rock (PR). This study aimed to determine whether struvite could be a component of a sustainable P fertiliser management strategy for arable crops.Methods
A combination of laboratory experiments, pot trials and mathematical modelling of the root system examined the P release properties of commercial fertiliser-grade struvite and patterns of P uptake from a low-P sandy soil by two different crop types, in comparison to more soluble inorganic P fertilisers (di-ammonium phosphate (DAP) and triple super phosphate (TSP)).Results
Struvite had greatly enhanced solubility in the presence of organic acid anions; buckwheat, which exudes a high level of organic acids, was more effective at mobilising struvite P than the low level exuder, spring wheat. Struvite granules placed with the seed did not provide the same rate of P supply as placed DAP granules for early growth of spring wheat, but gave equivalent rates of P uptake, yield and apparent fertiliser recovery at harvest, even though only 26 % of struvite granules completely dissolved. Fertiliser mixes containing struvite and DAP applied to spring wheat have potential to provide both optimal early and late season P uptake and improve overall P use efficiency.Conclusions
We conclude that the potential resource savings and potential efficiency benefits of utilising a recycled slow release fertiliser like struvite offers a more sustainable alternative to only using conventional, high solubility, PR-based fertilisers.69.
Gert‐Jan Bekker Benson Ma Narutoshi Kamiya 《Protein science : a publication of the Protein Society》2019,28(2):429-438
Single‐domain antibodies (sdAbs) function like regular antibodies, however, consist of only one domain. Because of their low molecular weight, sdAbs have advantages with respect to production and delivery to their targets and for applications such as antibody drugs and biosensors. Thus, sdAbs with high thermal stability are required. In this work, we chose seven sdAbs, which have a wide range of melting temperature (Tm) values and known structures. We applied molecular dynamics (MD) simulations to estimate their relative stability and compared them with the experimental data. High‐temperature MD simulations at 400 K and 500 K were executed with simulations at 300 K as a control. The fraction of native atomic contacts, Q, measured for the 400 K simulations showed a fairly good correlation with the Tm values. Interestingly, when the residues were classified by their hydrophobicity and size, the Q values of hydrophilic residues exhibited an even better correlation, suggesting that stabilization is correlated with favorable interactions of hydrophilic residues. Measuring the Q value on a per‐residue level enabled us to identify residues that contribute significantly to the instability and thus demonstrating how our analysis can be used in a mutant case study. 相似文献
70.
Dani Permana Kosuke Minamihata Tsuneyuki Tatsuke Jae M. Lee Takahiro Kusakabe Masahiro Goto Noriho Kamiya 《Biotechnology journal》2019,14(6)
The polymerization of proteins can create newly active and large bio‐macromolecular assemblies that exhibit unique functionalities depending on the properties of the building block proteins and the protein units in polymers. Herein, the first enzymatic polymerization of horseradish peroxidase (HRP) is reported. Recombinant HRPs fused with a tyrosine‐tag (Y‐tag) through a flexible linker at the N‐ and/or C‐termini are expressed in silkworm, Bombyx mori. Trametes sp. laccase (TL) is used to activate the tyrosine of Y‐tagged HRPs with molecular O2 to form a tyrosyl‐free radical, which initiates the tyrosine coupling reaction between the HRP units. A covalent dityrosine linkage is also formed through a HRP‐catalyzed self‐crosslinking reaction in the presence of H2O2. The addition of H2O2 in the self‐polymerization of Y‐tagged HRPs results in lower activity of the HRP polymers, whereas TL provides site‐selectivity, mild reaction conditions and maintains the activity of the polymeric products. The cocrosslinking of Y‐tagged HRPs and HRP‐protein G (Y‐HRP‐pG) units catalyzed by TL shows a higher signal in enzyme‐linked immunosorbent assay (ELISA) than the genetically pG‐fused HRP, Y‐HRP‐pG, and its polymers. This new enzymatic polymerization of HRP promises to provide highly active and functionalized polymers for biomedical applications and diagnostics probes. 相似文献