bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel biologically active eel calcitonin analogue with carboxyl terminal Hse32‐amide: Carboxyl terminal Pro32‐amide in calcitonin is not essential for biological activity
Authors: Yoshina Shigeaki , Ishida Tsutomu , Noda Hitoshi , Tomiya Noboru 
Published: July 2007

AbstractEel calcitonin (CT) analogues having C‐terminal homoserine (Hse)‐amide at position 31, 32, or 33 were synthesized, and in vivo hypocalcemic activity of the analogues were determined. The present study showed that: (i) An eel CT analogue having Hse‐amide at position 32 was more active than native eel CT, and the duration of hypocalcemic action of the analogue was equivalent to that of native eel CT. (ii) Either curtailment or elongation of [Hse32‐amide]‐eel CT peptide chain by one amino acid resulted in a great loss of hypocalcemic activity. The results of the present study indicate that Pro‐amide at the C‐terminus of CT is not essential for its biological activity in vivo. Replacement of C‐terminal Pro32‐amide by Hse32‐amide in eel CT molecule produced an analogue with a hypocalcemic activity greater than that of native eel CT.
Conformational change of cyclic AMP Receptor Protein by the binding of cyclic nucleotide
Authors: Park Sang‐Ho , Lec Tae‐Woo , Lee Bong‐Jin 
Published: July 2007

AbstractThe cAMP Receptor Protein (CRP) of Escherichia coli requires a conformational change induced by the binding of cAMP in order to function as a site‐specific DNA‐binding protein. An intrinsic fluorescence study showed that the tryptophan residues at position 13 and 85 within CRP were located in an internal, nonpolar environment, and the conformational change induced by the binding of cAMP occurred around the tryptophan residue. NMR experiment has manifested that the comformational change around the tryptophan residue at position 85 and histidine residue at position 159 of CRP is induced by the binding of cAMP. An extrinsic fluorescence study showed that the distance between the two cysteine 178 residues in the dimer was within about 3.5 Å. This distance didn't exhibit a large change upon cAMP binding.
IS‐RT‐PCR assay detection of MT‐MMP in a human breast cancer cell line
Authors: Haupt Larisa M. , Thompson Erik W. , Griffiths Lyn R. , Irving Michael G. 
Published: July 2007

AbstractThe in situ‐reverse transcription‐polymerase chain reaction (IS‐RT‐PCR) is a method that allows the direct localisation of gene expression. The method utilises the dual buffer mediated activity of the enzyme rTth DNA polymerase enabling both reverse transcription and DNA amplification. Labelled nucleoside triphosphates allow the site of expression to be labelled, rather than the PCR primers themselves, giving a more accurate localisation of transcript expression and decreased background than standard in situ hybridisation (ISH) assays. The MDA‐MB‐231 human breast carcinoma (HBC) cell line was assayed via the IS‐RT‐PCR technique, using primers encoding MT‐MMP (membrane‐type matrix metalloproteinase) and human β‐actin. Our results clearly indicate baseline expression of MT‐MMP in the relatively invasive MDA‐MB‐231 cell line at a signal intensity similar to the housekeeping gene β‐actin, and results following induction with Concanavalin A (Con A) are consistent with our previous results obtained via Northern blotting.
A phylogenetic study of Rubrobacter radiotolerans by sequence analysis of the 16S ribosomal RNA gene
Authors: Kausar Javed , Ohyama Yoshihiko , Yamamoto Osamu 
Published: July 2007

AbstractPartial sequence of the 16S ribosomal RNA gene of an extremely high radiotolerant bacterium, Rubrobacter radiotolerans (reclassified from Arthrobacter radiotoleransby chemical characteristics) was determined by PCR‐amplification from a small amount of heat‐lysed biomass, followed by direct sequencing of the PCR product. The sequence was aligned with seven species of Arthrobacter and also with representatives of various other bacterial groups. R. radiotolerans was confirmed to be out of the Arthrobacter group justifying the reclassification. Moreover, it has an individual position among the selected representatives being closer to the eubacterial groups.
Effects of ubiquinone enriched diet on deterioration of mitochondrial respiratory function caused by fried beef derived mutagenic factor in rats
Authors: Sugiyama Satoru , Yamada Koujirou , Hayakawa Mika , Esumi Hiroyasu , Ozawa Takayuki 
Published: July 2007

Abstract2‐Amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), a potent mutagenic agent produced during thermal processing of meats, shows detrimental effects on mitochondrial respiratory function. Effects of dietary ubiquinone‐10 was examined on PhIP‐induced mitochondrial respiratory dysfunction in rats. Rats fed with 0.2% ubiquinone‐10 diet mitigated the PhIP‐induced decrease in mitochondrial complex I activities observed in rat heart, diaphragm, and psoai major. Therefore, dietary anti‐oxidants such as ubiquinone‐10 could cancel out the unfavorable effects of PhIP and contribute to the preservation of mitochondrial function.
Cysteamine oxidation by lentil seedling amine oxidase
Authors: Medda Rosaria , Padiglia Alessandra , Lorrai Anita , De Marco Carlo , Floris Giovanni 
Published: July 2007

AbstractCysteamine is oxidatively deaminated by lentil amine oxidase. It shows saturation kinetic Km=9×10‐4 M like other substrates, but the aldehyde produced leads to loss of enzyme activity, which is restored by dialysis. When putrescine is the substrate of the amine oxidase cysteamine behaves like a competitive inhibitor, and shows Ki=5×10‐5 M. The possible involvement of the oxidation of cysteamine and the inhibitory effects of thioacetaldehyde in the cystamine oxidation by amine oxidase is discussed.
Kinetic study of the oxidation of 4‐hydroxyanisole catalyzed by tyrosinase
Authors: Espína J. C. , Varón R. , Tudela J. , García‐Cánovasa Francisco 
Published: July 2007

AbstractDespite the importance of the substrate 4‐hydroxyanisole in melanoma therapy, the kinetics of its oxidation catalyzed by tyrosinase has never been properly characterized. This approach is reported here for the first time. The applicability to 4‐hydroxyanisole of the reaction mechanism of tyrosinase previously proposed for other monophenols has been corroborated. The Michaelis constant for the oxidation of 4‐hydroxyanisole catalyzed by mushroom tyrosinase was (62±1.5jt]μM at pH 7 and increased when the pH decreased, reaching a value of (195±5jt]μM at pH 5.5. However the maximum steady‐state rate, whose value was (0.54±0.01jt]μM/min, did not change with the pH. The apparent catalytic constant was (184±5jt]s‐1, around twenty three times higher than that previously described for L‐tyrosine (8 s‐l).
cDNA sequence analysis of cardiotoxin variants from Taiwan cobra
Authors: Chang Long‐Sen , Lin Jordge , Wu Pei‐Fung 
Published: July 2007

AbstractFive cDNAs encoding cardiotoxin variants were constructed from the cellular RNA isolated from the venom glands of Naja naja atra by reverse transcription‐polymerase chain reaction. A high degree of nucleotide sequence homology was observed between these variants and other determined ones. Among them, a novel cardiotoxin 6 had 61 amino acid residues rather than 60 ones that usually observed with Naja naja atra cardiotoxins. The other cardiotoxin variants were the homologues of cardiotoxins 1, V or N with one or two amino acid substitutions, respectively. These results probably reflect the involvement of RNA editing in the production of cardiotoxin variants in the venom of Taiwan cobra.
cDNA‐derived amino‐acid sequence of a land turtle (Geochelone carbonaria) β‐chain hemoglobin
Authors: Bordin Silvana , Meza Andréia N. , Saad Sara T. O. , Ogo Satie H. , Costa Fernando F. 
Published: July 2007

AbstractThe cDNA sequence encoding the turtle Geochelone carbonaria β‐chain was determinated. The isolation of hemoglobin mRNA was based on degenerate primers' PCR in combination with 5′‐ and 3′‐RACE protocol. The full length cDNA is 615 bp with the ATG start codon at position 53 and TGA stop codon at position 495; The AATAAA polyadenylation signal is found at position 599. The deduced polypeptyde contains 146 amino‐acid residues. The predicted amino acid sequence shares 83% identity with the β‐globin of a related specie, the aquatic turtle C. p. belli. Otherwise, identity is higher when compared with chicken β‐Hb (80%) than with other reptilian orders (Squamata, 69%, and Crocodilia, 61%). Compared with human HbA, there is 67% identity, and at least three amino acid substitutions could be of some functional significance (Glu43β‐→Ser, His 116β→Thr and His143β→Leu). To our knowledge this represents the first cDNA sequence of a reptile globin gene described.
Variable requirement for splicing signals for nucleocytoplasmic export of mRNAs
Authors: Fu Litao , Suen Christine K. M. , Waseem Ahmed , White Kenneth N. 
Published: July 2007

AbstractUsing in situ hybridisation to detect tile intracellular localisation of mRNAs we have found that mRNAs expressed from intronless cDNAs of normally intronic genes are expressed well but largely retained ill nuclei. The degree of nuclear retention is quite variable but in all cases addition of splicing signals to the expression cassette are required for efficient export of the mRNAs from nucleus to cytoplasm. In contrast mRNAs expressed from the intronless genes of hamster β‐adrenergic receptor and human serotonin receptor type 1A showed very little nuclear accumulation and strong expression in the cytoplasm independently of splicing signals. The data demonstrate a link between splicing and export and dissemble from the idea that splicing enhances mRNA expression by protecting nascent nuclear mRNAs from degradation.
Synthesis and imaging of blood‐brain‐barrier permeable nitroxyl‐probes for free radical reactions in brain of living mice
Authors: Sano Hiroaki , Matsumoto Ken‐ichiro , Utsumi Hideo 
Published: July 2007

AbstractThree different lipophilic nitroxyl‐probes having capability to pass the blood‐brain barrier were, for the ftrst time, synthesized to estimate free radical reactions in brain of living animals. Two of the three were designed to be hydrolyzed by esterase and remain in cell. All 3 probes had high n‐octanol/buffer partition coefficients and gave 2 signal components in in vivo ESR spectra at head of living mice after intravenous injection. The ESR parameters of 2 components agreed with those of probes dissolved in water and lipidic phases. The ESR‐CT imaging on the nilroxyl‐proves after intravenous injection revealed that all probes presented in both encephalon and extracranial region of head. Tissue distribution of the nitroxyl‐probes demonstrated that the newly synthesized lipophilic nitroxyl‐probes had capability to pass the blood‐brain barrier and accumulated in brain than that of hydrophilic probe.
Residues K128‐Q175 of human interleukin‐6 are essential for its biological activity
Authors: Liu Haitian , Duan Jubao , Wang Jiaxi , Peng Shanyun , Zou Minji 
Published: July 2007

AbstractInternal deletion K128‐Q175 of the human interleukin‐6 (hIL‐6) has been generated at the cDNA level. With pBV220 as expressing vector, the recombinant pBV*‐DIL‐6 encoding the deletion mutant (12kD) of hIL‐6 has been constructed. The resulted recombinant plasmids were then used to transform E. coli strain HB101, and the expression in the PLPR promoter system, which is temperature‐regulatable, was achieved. After purification and renaturation, the biological activity of the expressed product, designated as DM120, was measured by MTT method in an IL‐6‐dependent cell line 7TD1. The results show that the amino acid residues of IL‐6 128 to 175 are crucial for IL‐6 activity. Receptor binding assay in vitro indicates that the entire region is not involved in forming the receptor binding surface.
Myofibrils of skeletal muscle: The activity coefficient of orthophosphate
Authors: Grazi Enrico , Adami Raffaella , Magri Ermes , Trombetta Giorgio , Frassinefi Chiara 
Published: July 2007

AbstractIn the myofibrils of skeletal muscle, at 22°C, pH 7.1 and at the physiological protein osmotic pressure of 1.8×105 dynes/cm2, orthophosphate behaves quite ideally, the activity coefficient being 0.85. Under the same conditions and at saturation, 2.67 μ moles of orthophosphate are bouud per gram of dry myofibrils, with a dissociation constant of 7×10‐5 molal.Work is in progress to determine the activity coefficients of adenine nucleotide analogues. This work is needed to assess the actual value of the free energy of hydrolysis of ATP in muscle.
Bio‐normalizer modulates interferon‐γ‐induced nitric oxide production in the mouse macrophage cell line RAW 264.7
Authors: Kobuchi Hirotsugu , Packer Lester 
Published: July 2007

AbstractBio‐Normalizer, a natural health food supplement prepared from Carica papaya and some other medicinal plants was investigated to determine its effects on cellular nitric oxide (nitrogen monoxide, NO) production and inducible nitric oxide synthase (iNOS) expression. Bio‐Normalizer upregulated interferon (IFN)‐γ‐induced NO production by macrophages in a dose‐dependent manner. Such an effect of Bio‐Normalizer on NO production was not due to changes in the activity of iNOS. Reverse transcription‐potymerase chain reaction analysis revealed that the levels of iNOS mRNA were augmented by treatment of the cells with Bio‐Normalizer and IFN‐γ. The ability of Bio‐Normalizer to augment IFN‐γ‐induced iNOS mRNA expression was independent of any changes on the mRNA stability. Treatment of cells with Bio‐Normalizer alone did not affect NO production by macrophages. Tumor necrosis factor‐α and interleukin‐1β are involved in the induction of iNOS gene as well as the immune system. Bio‐Normalizer augmented the mRNA expression of these cytokines in the presence of IFN‐γ. This suggests that Bio‐Normalizer is not directly involved in the expression of iNOS, but shows synergistic interaction with IFN‐γ to induce NO synthesis.
Purification and characterization of an endoglucanase from the marine rotifer, Brachionus plicatilis
Authors: Chun Chang Zoon , Kim Young Tae , Hur Sung Bum 
Published: July 2007

AbstractThe marine rotifer, Brachionus plicatilis, is able to digest Chlorella efficiently, suggesting that the rotifer contains a powerful cellulolytic enzyme system. A multi‐component cellulolytic complex, including endoglucanase (CM‐cellulase), cellobiohydrolase and β‐glucosidase, was found in Brachionus plicatilis. Endoglucanase (endo‐β‐1,4 glucanase) was purified to homogeneity from rotifer homogenates using a sequential chromatographic method. The purified enzyme exhibits a strong hydrolytic activity with carboxymethyl(CM)‐cellulose. The optimum temperature and pH for the endoglucanase activity were 37 °C and 7.0, respectively. 80% of the CM‐cellulase activity was retained in salt mixture that ranged from 150 to 500 mM NaCl equivalent. The purified protein was isolated with a molecular weight of approximately 62 kDa estimated by SDS‐polyacrylamide gel electrophoresis.
Novel substrates of yeast alcohol dehydrogenase ‐ 3. 4‐dimethylamino‐cinnamaldehyde and chloroacetaldehyde
Authors: Leskovac V. , Trivic S. , Zeremski J. , Stancic B. , Anderson B. M. 
Published: July 2007

Abstract4‐Dimethylamino‐trans‐cinnamaldehyde and chloroacetaldehyde are novel substrates of yeast alcohol dehydrogenase (EC 1.1.1.1). In the present work, we have reported the steady‐state kinetic constants for both substrates, and their chemical reactions with the enzyme protein itself. Both substrates are potentially useful for biotechnology, chemoenzyme syntheses and analytical biochemistry.
Cloning and sequencing of the secY gene homolog from Mycobacterium bovis BCG
Authors: Kim Jin Koo , Kim Jeong Hyun , Kim Jae Wha , Lee Younghee , Lim Jong‐Seok , Lee Hee Gu , Choe In Seong , Chung Tai Wha , Park Sue‐Nie , Ahn Jong Seog , Choe Yong‐Kyung , Kim Sang Jae , Bai Gill Han , Cho Sang‐Hyun , Kang Sang Won , Kim Yu Sam 
Published: July 2007

AbstractThe complete nucleotide sequence of a 1,513 bp fragment of Mycobacterium bovis BCG containing the secY gene homolog and partial adk gene that encodes an adenylate kinase has been determined. The secY gene of BCG has an open reading frame of 441 amino acids with homology to the SecY protein family. Comparative analyses of the deduced amino acid sequence of additional partial ORF revealed strong similarity to the known adenylate kinases.
Immunohistochemical analysis of heme oxygenase‐I in rat liver after ischemia
Authors: Ito Koji , Ikeda Satoru , Shibata Toshikazu , Yano Tomohiro , Horikawa Saburo 
Published: July 2007

AbstractTotal hepatic ischemia was induced by clamping the hepatic artery, portal vein, and bile duct. After 15 min hepatic ischemia, we examined a time course of the changes in the steady‐state levels of heme oxygenase‐1 (HO‐1) mRNA and protein in the livers. The levels of HO‐1 mRNA was transiently induced and peaked at 4 h after the start of reperfusion. In addition, a pattern of the time course of HO‐1 protein levels was similar to that of HO‐1 mRNA levels. Immunohistochemical analysis clearly showed that the localization of HO‐1 protein induced by hepatic ischemia was restricted to the hepatoeytes in the pericentral vein.
Cloning of the human cDNA sequence encoding the NADH: Ubiquinone oxidoreductase MLRQ subunit
Authors: Kim Jae Wha , Lee Younghee , Kang Ho Bum , Choe Yong Kyung , Chung Tae Wha , Chang Sung Yeoul , Lee Kwang Soo , Choe In Seong 
Published: July 2007

AbstractA cDNA clone encoding human NADH:ubiquinone oxidoreductase (complex I of mitochondrial respiratory chain) MLRQ subunit was isolated from human fetal liver cDNA library. The clone contained an open reading frame of 246 bp which predicted a protein comprising 81 amino acids with a calculated molecular weight of 9,370 Da. The deduced amino acid sequence exhibited 95% homology (88% identity and 7% favored substitution) to that of bovine MLRQ subunit. Northern analysis revealed that the cDNA clone hybridized with a 0.7 kb mRNA species which was present in all tissues examined. The expression level of the 0.7 kb mRNA in heart, skeletal muscle, and brain was higher than in other organs. Human MLRQ cDNA could cross‐hybridize with the genomic DNAs from various species.
A study of supramolecular organization of glycogenolytic enzymes in vertebrate muscle tissue
Authors: Shmelev V. K. , Serebrenikova T. P. 
Published: July 2007

AbstractUnder conditions preventing the direct binding of phosphorylase kinase to glycogen, we detected the formation of the compound ternary complex of glycogen, phosphorylase and phosphorylase kinase. The complex formation occurs in two stages: (i) the formation of phosphorylase‐glycogen complex controlled by ATP, (ii) the binding of phosphorylase kinase to the previously formed phosphorylase‐glycogen complex exclusively in the presence of Ca2+ and Mg2+. The process is responsible for the increase of phosphorylase kinase activity in the presence of glycogen. An opinion is offered that a specific order of enzyme binding to glycogen particle as support provides for a self‐assembly of the studied metabolon and plays an essential role in the regulation of glycogenolysis.
The effects of imidazoacridinones, new antineoplastic agents, on the human erythrocyte membrane
Authors: Józwiak Zofia , Pacholska Marzena , Szwarocka Agnieszka 
Published: July 2007

AbstractIn the present study, the interactions of imidazoacridinones, C‐1311 and C‐1371 with human erythrocyte membranes were examined by electron spin resonance spectroscopy (ESR). It was observed that both compounds C‐1311 and C‐1371 preferentially bind to proteins producing the conformational changes of erythrocyte membrane skeletal proteins.
Cloning of a novel retinoic acid‐inducible mRNA from human osteoblast‐like cells
Authors: Melhus Håkan , Wilén Birgitta , Kindmark Andreas , Ljunghall Sverker 
Published: July 2007

AbstractRetinoids have long been known to influence skeletal development and bone remodeling. Cells of the osteoblastic lineage play a key role in these processes. In this study we have used the differential display PCR technique to identify retinoic acid (RA)‐induced mRNAs in human osteoblast‐like cells. We report the cloning and sequencing of one such mRNA, AT‐RA 6, which was specifically induced by all‐trans RA both in normal human osteoblast‐like cells and in MG‐63 osteosarcoma cells. Maximal expression was found after 60 min, suggesting that this may be an early response gene. Expression was found in all tissues examined. No homology to known mRNA sequences was detected.
Investigation of the effect of lannate on kinetic parameters of acetylcholinesterase: Slightly concave mixed‐type of inhibition system
Authors: Kamal Mohammad Amjad 
Published: July 2007

AbstractThe effect of lannate on kinetic parameters of camel retina acetylcholinesterase is investigated in the present study. The Ks for the hydrolysis of acetylthiocholine iodide was found to be 0.086 mM in the control system; a value that increased in the lannate treated systems. The Vmax was 0.853 μmole/min/mg protein for the control system while it decreased in the lannate treated systems. Dixon as well as Lineweaver‐Burk plots and their secondary replots indicated that the nature of the inhibition is of the slightly concave mixed type, which is considered to be a 'semi‐pure competitive' and 'semi‐partial as well as semi‐pure non‐competitive' mixture. The values of Ki(slope) and KI (intercept) were estimated as 0.143 μM and 0.179 μM respectively. The KI was greater than Ki indicating that lannate has a greater affinity of binding for the peripheral site than the active site of the camel retina AChE.
Anti‐ROS‐DNA monoclonal antibody as molecular probe for oxidative DNA damage
Authors: Ashok Badithe T. , Ahmad Jabeen , Ali Rashid , Qadri Ayub 
Published: July 2007

AbstractModification of 400 bp (approximate size) calf thymus DNA with OH radical resulted in lowered Tm, modification of thymine (58.3%), guanine (20%) and single strand breaks. Monoclonal antibodies (mAb) generated against ROS‐DNA were of IgG1 subclass. The mAb showed strong binding to ROS‐DNA and ROS‐modified bases and polymers, in particular, of thymine. The mAb, therefore, preferentially recognizes ROS‐modified epitopes on nucleic acids. Distinct binding to DNA isolated from aged, but not from normal humans by the monoclonal antibdy was observed. The antibody effectively recognized oxidative lesions in DNA from cancer patients. These studies demonstrate the potential application of the mAb as an immunochemical probe to detect oxidative DNA lesions.
The essential tryptophan residues of pig kidney aminoacylase
Authors: Chen Rong , Xu Dong , Zhou Hai‐Meng 
Published: July 2007

AbstractThe tryptophan residues in pig kidney aminoacylase (N‐acylamino acid amido hydrolase, EC 3.5.1.14) have been modified by N‐bromosuccinimide (NBS) at low pH. The modification of eight tryptophan residues as measured by spectrophotometric and spectrofluorimetric methods leads to complete loss of enzymatic activity. The decreases in absorption at 280 nm and fluorescence emission at 337 nm indicate the modification of tryptophan residues. Both the inactivation and tryptophan residual modification are monophasic, first‐order reactions. Quantitative treatment of the data (Tsou, C. L., Sci. Sin., 1962, 11, 1535‐1558) shows that among the tryptophan residues modified, two are essential for aminoacylase catalytic activity. Kördel and Schneider (Hoppe‐Seyler's Physiol. Chem. 1976, 357, 1109‐1115) reported that the modification of tryptophan residues led to inactivation of aminoacylase, and suggested that tryptophan residues are essential for enzymatic activity. We have now shown that eight tryptophan residues can be modified by N‐bromosuccinimide and that two of them are essential for the catalytic activity of this enzyme.