排序方式: 共有79条查询结果,搜索用时 15 毫秒
71.
Jinda Jandaruang Jaruwan Siritapetawee Chomphunuch Songsiriritthigul Sutthidech Preecharram Taoka Azuma Apisak Dhiravisit Yoshihiro Fukumori Sompong Thammasirirak 《The protein journal》2014,33(4):377-385
Crocodylus siamensis hemoglobin was purified by a size exclusion chromatography, Sephacryl S-100 with buffer containing dithiothreitol. The purified Hb was dissociated to be two forms (α chain and β chain) which observed by SDS-PAGE, indicated that the C. siamensis Hb was an unpolymerized form. The unpolymerized Hb (composed of two α chains and two β chains) showed high oxygen affinity at 3.13 mmHg (P50) and 1.96 (n value), and a small Bohr effect (δH+ = ?0.29) at a pH of 6.9–8.4. Adenosine triphosphate did not affect the oxygenation properties, whereas bicarbonate ions strongly depressed oxygen affinity. Crude C. siamensis Hb solutions were showed high O2 affinity at P50 of 2.5 mmHg which may assure efficient utilization of the lung O2 reserve during breath holding and diving. The purified Hbs were changed to cyanmethemoglobin forms prior crystallization. Rod- and plate-shaped crystals were obtained by the sitting-drop vapor-diffusion method at 5 °C using equal volumes of protein solution (37 mg/ml) and reservoir [10–13 % (w/v) PEG 4000, with 0.1 M Tris buffer in present of 0.2 M MgCl2·6H2O] solution at a pH of 7.0–8.5. 相似文献
72.
Pornpimol Ponkham Sakda Daduang Wachira Kitimasak Chartchai Krittanai Daranee Chokchaichamnankit Chantragan Srisomsap Jisnuson Svasti Shunsuke Kawamura Tomohiro Araki Sompong Thammasirirak 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2010,151(1):75-83
To study the structure and function of reptile lysozymes, we have reported their purification, and in this study we have established the amino acid sequence of three egg white lysozymes in soft-shelled turtle eggs (SSTL A and SSTL B from Trionyx sinensis, ASTL from Amyda cartilaginea) by using the rapid peptide mapping method. The established amino acid sequence of SSTL A, SSTL B, and ASTL showed substitutions of 43, 42, and 44 residues respectively when compared with the HEWL (hen egg white lysozyme) sequence. In these reptile lysozymes, SSTL A had one substitution compared with SSTL B (Gly126Asp) and had an N-terminal extra Gly and 11 substitutions compared with ASTL. SSTL B had an N-terminal extra Gly and 10 residues different from ASTL. The sequence of SSTL B was identical to soft-shelled turtle lysozyme from STL (Trionyx sinensis japonicus). The Ile residue at position 93 of ASTL is the first report in all C-type lysozymes. Furthermore, amino acid substitutions (Phe34His, Arg45Tyr, Thr47Arg, and Arg114Tyr) were also found at subsites E and F when compared with HEWL. The time course using N-acetylglucosamine pentamer as a substrate exhibited a reduction of the rate constant of glycosidic cleavage and increase of binding free energy for subsites E and F, which proved the contribution for amino acids mentioned above for substrate binding at subsites E and F. Interestingly, the variable binding free energy values occurred on ASTL, may be contributed from substitutions at outside of subsites E and F. 相似文献
73.
Thammasirirak S Ponkham P Preecharram S Khanchanuan R Phonyothee P Daduang S Srisomsap C Araki T Svasti J 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2006,143(2):209-217
Cation exchange column chromatography and gel filtration chromatography were used to purify four reptile lysozymes from egg white: SSTL A and SSTL B from soft shelled turtle (Trionyx sinensis), ASTL from Asiatic soft shelled turtle (Amyda cartilagenea) and GSTL from green sea turtle (Chelonia mydas). The molecular masses of the purified reptile lysozymes were estimated to be 14 kDa by SDS-PAGE. Enzyme activity of the four lysozymes could be confirmed by gel zymograms and showed charge differences on native-PAGE. SSTL A, SSTL B and ASTL had sharp pH optima of about pH 6.0, which contrasts with that of GSTL, which showed dual pH optima at about pH 6.0 and pH 8.0. The activities of the reptile lysozymes rapidly decreased within 30 min of incubation at 90 degrees C except for ASTL, which was more stable. Partial N-terminal amino acid sequencing and peptide mapping strongly suggested that the enzymes were C-type lysozymes. Interestingly, the mature SSTL lysozymes show an extra Gly residue at the N-terminus, which was previously found in soft-shelled turtle lysozyme. The reptile lysozymes showed lytic activity against several species of bacteria, such as Micrococcus luteus and Vibrio cholerae, but showed only weak activity to Pseudomonas aeruginosa and lacked activity towards Aeromonas hydrophila. 相似文献
74.
Inoculation of sugar mill by-products compost with N2-fixing bacteria may improve its quality by increasing total N and available P. Compost was inoculated with Azotobacter vinelandii(ATCC 478), Beijerinckia derxii (ATCC 49361), and Azospirillumsp. TS8, each alone and all three together. Numbers of all N2-fixing bacteria in compost declined from an initial population of 5×105cellsg–1 during incubation. The population of Azotobacter declined to approximately 2×102cellsg–1 and the population of Beijerinckia and Azospirillum declined to approximately 9×103 and 3.5×104cellsg–1 respectively, at day 50. Inoculation with N2-fixing bacteria increased acetylene reduction, total N by 6–16 and available P by 25–30% in comparison to the uninoculated control. Increasing the N content and P availability of compost increases its value and there may be additional benefit from providing N2 fixing bacteria. 相似文献
75.
Dynamic interaction of the measles virus hemagglutinin with its receptor signaling lymphocytic activation molecule (SLAM, CD150) 总被引:1,自引:0,他引:1
Navaratnarajah CK Vongpunsawad S Oezguen N Stehle T Braun W Hashiguchi T Maenaka K Yanagi Y Cattaneo R 《The Journal of biological chemistry》2008,283(17):11763-11771
The interaction of measles virus with its receptor signaling lymphocytic activation molecule (SLAM) controls cell entry and governs tropism. We predicted potential interface areas of the measles virus attachment protein hemagglutinin to begin the investigation. We then assessed the relevance of individual amino acids located in these areas for SLAM-binding and SLAM-dependent membrane fusion, as measured by surface plasmon resonance and receptor-specific fusion assays, respectively. These studies identified one hemagglutinin protein residue, isoleucine 194, which is essential for primary binding. The crystal structure of the hemagglutinin-protein localizes Ile-194 at the interface of propeller blades 5 and 6, and our data indicate that a small aliphatic side chain of residue 194 stabilizes a protein conformation conducive to binding. In contrast, a quartet of residues previously shown to sustain SLAM-dependent fusion is not involved in binding. Instead, our data prove that after binding, this quartet of residues on propeller blade 5 conducts conformational changes that are receptor-specific. Our study sets a structure-based stage for understanding how the SLAM-elicited conformational changes travel through the H-protein ectodomain before triggering fusion protein unfolding and membrane fusion. 相似文献
76.
Prawit Kongjan Sompong O‐Thong Meher Kotay Booki Min Irini Angelidaki 《Biotechnology and bioengineering》2010,105(5):899-908
Hydrolysate was tested as substrate for hydrogen production by extreme thermophilic mixed culture (70°C) in both batch and continuously fed reactors. Hydrogen was produced at hydrolysate concentrations up to 25% (v/v), while no hydrogen was produced at hydrolysate concentration of 30% (v/v), indicating that hydrolysate at high concentrations was inhibiting the hydrogen fermentation process. In addition, the lag phase for hydrogen production was strongly influenced by the hydrolysate concentration, and was prolonged from approximately 11 h at the hydrolysate concentrations below 20% (v/v) to 38 h at the hydrolysate concentration of 25% (v/v). The maximum hydrogen yield as determined in batch assays was 318.4 ± 5.2 mL‐H2/g‐sugars (14.2 ± 0.2 mmol‐H2/g‐sugars) at the hydrolysate concentration of 5% (v/v). Continuously fed, and the continuously stirred tank reactor (CSTR), operating at 3 day hydraulic retention time (HRT) and fed with 20% (v/v) hydrolysate could successfully produce hydrogen. The hydrogen yield and production rate were 178.0 ± 10.1 mL‐H2/g‐sugars (7.9 ± 0.4 mmol H2/g‐sugars) and 184.0 ± 10.7 mL‐H2/day Lreactor (8.2 ± 0.5 mmol‐H2/day Lreactor), respectively, corresponding to 12% of the chemical oxygen demand (COD) from sugars. Additionally, it was found that toxic compounds, furfural and hydroxymethylfurfural (HMF), contained in the hydrolysate were effectively degraded in the CSTR, and their concentrations were reduced from 50 and 28 mg/L, respectively, to undetectable concentrations in the effluent. Phylogenetic analysis of the mixed culture revealed that members involved hydrogen producers in both batch and CSTR reactors were phylogenetically related to the Caldanaerobacter subteraneus, Thermoanaerobacter subteraneus, and Thermoanaerobacterium thermosaccharolyticum. Biotechnol. Bioeng. 2010;105: 899–908. © 2009 Wiley Periodicals, Inc. 相似文献
77.
Albert Schulte Sompong Ruamchan Panida Khunkaewla Wipa Suginta 《The Journal of membrane biology》2009,230(2):101-111
Vibrio harveyi is known to cause fatal vibriosis in marine animals. Here, an outer membrane protein from V. harveyi, namely, VhOmp, was isolated and functionally characterized in terms of pore-forming contact with artificial lipid membranes.
The native VhOmp exists as a trimer of a molecular weight similar to that of the porin OmpF from Escherichia coli. Reconstitution of VhOmp into black lipid membranes demonstrated its ability to form ion channels. The average pore conductance
of VhOmp was revealed to be about 0.9 and 2 nS in 0.2 and 1 M KCl, respectively. Within transmembrane potentials of ±100 mV,
VhOmp pores behaved as ohmic conduits, and their conductance scaled linearly with voltage. Nonlinear plots of the pore conductance
versus symmetrical salt concentrations at either side of the protein-incorporating membrane suggested the influence of interior
channel functionalities on the passage of charged species. In the presence of Omp-specific polyclonal antibodies, the pore-forming
property of VhOmp was modulated so that the usual step-like current increments were replaced by random transitory current
fluctuations. VhOmp exhibited a strong biological activity by causing hemolysis of human red blood cells, indicating that
VhOmp may act as a crucial determinant during bacterial infection to animal host cells. 相似文献
78.
Preeyanan Anwised Thai Kabbua Theeranan Temsiripong Apisak Dhiravisit Sarawut Jitrapakdee Tomohiro Araki Kazunari Yoneda Sompong Thammasirirak 《The protein journal》2013,32(3):172-182
The first report of complete nucleotide sequences for α- and β-globin chains from the Siamese hemoglobin (Crocodylus siamensis) is given in this study. The cDNAs encoding α- and β-globins were cloned by RT-PCR using the degenerate primers and by the rapid amplification of cDNA ends method. The full-length α-globin cDNA contains an open reading frame of 423 nucleotides encoding 141 amino acid residues, whereas the β-globin cDNA contains an open reading frame of 438 nucleotides encoding 146 amino acid residues. The authenticity of both α- and β-globin cDNA clones were also confirmed by the heterologous expression in Escherichia coli (E. coli). This is the first time that the recombinant C. siamensis globins were produced in prokaryotic system. Additionally, the heme group was inserted into the recombinant proteins and purified heme-bound proteins were performed by affinity chromatography using Co2+-charged Talon resins. The heme-bound proteins appeared to have a maximum absorbance at 415 nm, indicated that the recombinant proteins bound to oxygen and formed active oxyhemoglobin (HbO2). The results indicated that recombinant C. siamensis globins were successfully expressed in prokaryotic system and possessed an activity as ligand binding protein. 相似文献
79.
Saowaluck Srihongthong Anawat Pakdeesuwan Sakda Daduang Tomohiro Araki Apisak Dhiravisit Sompong Thammasirirak 《The protein journal》2012,31(6):466-476
Hemoglobin, ??-chain, ??-chain and fragmented hemoglobin of Crocodylus siamensis demonstrated both antibacterial and antioxidant activities. Antibacterial and antioxidant properties of the hemoglobin did not depend on the heme structure but could result from the compositions of amino acid residues and structures present in their primary structure. Furthermore, thirteen purified active peptides were obtained by RP-HPLC analyses, corresponding to fragments in the ??-globin chain and the ??-globin chain which are mostly located at the N-terminal and C-terminal parts. These active peptides operate on the bacterial cell membrane. The globin chains of Crocodylus siamensis showed similar amino acids to the sequences of Crocodylus niloticus. The novel amino acid substitutions of ??-chain and ??-chain are not associated with the heme binding site or the bicarbonate ion binding site, but could be important through their interactions with membranes of bacteria. 相似文献