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1.
John J. Marchalonis Fatma Dedeoglu Hulya Kaymaz Samuel F. Schluter Allen B. Edmundson 《Journal of Protein Chemistry》1992,11(2):129-137
Although the amino acid sequence and three-dimensional structure of human immunoglobulin light chains have been known for more than 15 years, the location of antigenic markers characteristic of chains has not been determined. Here, we use a set of synthetic overlapping peptides to completely model the sequence of the chain Mcg and test these for the binding or rabbit and goat antisera specific for chain determinants. We assess peptide contributions to -antigenic reactivity and also to identify a portion of C-region where conformational factors contribute to the antigenicity. Specific determinants occur both in the constant and variable (first and third framework) domains of the molecule. The fourth framework of the variable region, a segment specified by the joining gene, is also recognized and cross-reacts antigenically with the homologous region of T cell receptor chains. Major specific determinants are localized in the N- and C-terminal segments, which are linear and devoid of major conformational folding. Other segments that are strongly antigenic, such as the third framework of the V region (residue 78–93) and a segment of the constant region (residues 177–192), show strong conformational dependence in antigenicity. 相似文献
2.
We investigated the effect of PON 55 and PON 192 polymorphisms on serum PON1 activity and lipid profiles in 213 non-insulin dependent diabetes mellitus (NIDDM) individuals and 116 non-diabetic controls among Turkish subjects. The distribution of PON 55/192 gene polymorphism was determined by polymerase chain reaction-based restriction fragment length polymorphism. Serum lipid levels were measured enzymically. PON activity was measured by spectrophotometric assay of p-nitrophenol production following addition of paraoxon. We found that PON 55 and 192 genotype distribution was similar in patients and controls and paraoxonase activity was generally lower in diabetics than in control subjects. We showed that PON 55 and 192 genotypes have a major effect on serum PON activity. PON 192 BB homozygotes had significantly higher PON activity than AA and AB genotypes among the control and NIDDM populations (p<0.001). PON 55 MM homozygotes had significantly lower PON activity than did LL and LM genotypes in control and NIDDM populations (p<0.05). The PON1 55 and 192 polymorphisms did not consistently influence the serum lipid profiles in either population. In conclusion, our results suggest that the paraoxonase activities are affected by PON1 genetic variability in Turkish NIDDM patients and controls. 相似文献
3.
İlhami Gülçin Andrea Scozzafava Claudiu T. Supuran Hulya Akıncıoğlu Zeynep Koksal Fikret Turkan 《Journal of enzyme inhibition and medicinal chemistry》2016,31(6):1095-1101
Caffeic acid phenethyl ester (CAPE) is an active component of honeybee propolis extracts. Carbonic anhydrases (CAs, EC 4.2.1.1) are widespread and intensively studied metalloenzymes present in higher vertebrates including humans as many diverse isoforms. Acetylcholinesterase (AChE) is responsible for acetyl choline (ACh) hydrolysis and plays a fundamental role in nerve impulse transmission by terminating the action of the ACh neurotransmitter at cholinergic synapses and neuromuscular junctions. Butyrylcholinesterase (BChE) is another enzyme abundantly present in the liver and released into blood in a soluble form. Lactoperoxidase (LPO) is an enzyme involved in fighting pathogenic microorganisms whereas glutathione S-transferases (GSTs) are dimeric proteins present both in prokaryotic and eukaryotic organisms and involved in cellular detoxification mechanisms. In the present study, the inhibition effect of CAPE on human carbonic anhydrase (hCA) isoforms I, II, IX, and XII, AChE, BChE, LPO, and GST was evaluated. CAPE inhibited these enzymes with Kis in the range between micromolar to picomolar. The best inhibitory effect was observed against AChE and BChE. 相似文献
4.
Dokmeci D Inan M Basaran UN Yalcin O Aydogdu N Turan FN Uz YH 《Cell biochemistry and function》2007,25(6):611-618
Testicular torsion is a urological emergency referred to as 'acute scrotum', because inappropriate treatment can lead to male subfertility and infertility. A possible cause of testicular damage is the ischaemia-reperfusion (I/R) injury attributed to oxygen free radicals. L-carnitine, a vitamin-like antioxidant, plays a pivotal role in the maturation of spermatozoa within the reproductive tract. The aim of the present paper was to determine the protective effect of L-carnitine on testicular I/R-induced injury. Thirty-two male rats were divided into 4 groups (n = 8). Testicular torsion was created by rotating the right testis 720 degrees in a clockwise direction. Group 1: sham-operated control; group 2: ischaemia; group 3: I/R; group 4: ischaemia-L-carnitine treatment-reperfusion group. L-carnitine (500 mg kg(-1), intraperitoneally) was administered before 30 min of detorsion in Group 4. After torsion (5 h) and detorsion (5 h), bilateral orchidectomy was performed. The malondialdehyde (MDA) level was evaluated in testes. Histopathologically, Johnsen's spermatogenesis criteria and mean seminiferous tubule diameter (MSTD) measurements were used. Testicular MDA levels were higher in the torsion group compared to the sham-control group (p < 0.05). Detorsion (reperfusion) caused a further increase in MDA levels (p < 0.05). Pretreatment with L-carnitine prevented a further increase in MDA levels (p < 0.05). Histologically, torsion caused some separation among germinal cells in the seminiferous tubules, which became much more prominent in the I/R group but was attenuated with L-carnitine pretreatment. In conclusion, L-carnitine pretreatment may have a protective effect in experimental testicular torsion-detorsion model in rats by its well-known antioxidant potential. 相似文献
5.
Kenneth N. Mertens Sofia Ribeiro Ilham Bouimetarhan Hulya Caner Nathalie Combourieu Nebout Barrie Dale Anne De Vernal Marianne Ellegaard Mariana Filipova Anna Godhe Evelyne Goubert Kari Grøsfjeld Ulrike Holzwarth Ulrich Kotthoff Suzanne A.G. Leroy Laurent Londeix Fabienne Marret Kazumi Matsuoka Peta J. Mudie Lieven Naudts Stephen Louwye 《Marine Micropaleontology》2009,70(1-2):54-69
A biometrical analysis of the dinoflagellate cyst Lingulodinium machaerophorum [Deflandre, G., Cookson, I.C., 1955. Fossil microplankton from Australia late Mesozoic and Tertiary sediments. Australian journal of Marine and Freshwater Research 6: 242–313.] Wall, 1967 in 144 globally distributed surface sediment samples revealed that the average process length is related to summer salinity and temperature at a water depth of 30 m by the equation (salinity/temperature) = (0.078?average process length + 0.534) with R2 = 0.69. This relationship can be used to reconstruct palaeosalinities, albeit with caution. The particular ecological window can be associated with known distributions of the corresponding motile stage Lingulodinium polyedrum (Stein) Dodge, 1989. Confocal laser microscopy showed that the average process length is positively related to the average distance between process bases (R2 = 0.78), and negatively related to the number of processes (R2 = 0.65). These results document the existence of two end members in cyst formation: one with many short, densely distributed processes and one with a few, long, widely spaced processes, which can be respectively related to low and high salinity/temperature ratios. Obstruction during formation of the cysts causes anomalous distributions of the processes. From a biological perspective, processes function to facilitate sinking of the cysts through clustering. 相似文献
6.
The increase of Mg2+, from 1.3 to 3 microM, in growth medium of F. equiseti and F. acuminatum increased intracellular magnesium levels from 0.83 and 0.81 microM to 1.75 and 1.42 microM on the 12th day, respectively. Intracellular magnesium levels also elevated depending upon the number of incubation days. The maximum manganese levels of F. equiseti and F. acuminatum obtained in 1.6 microM Mg2+ culture medium were 0.67 and 1.23 microM, while maximum iron levels were determined to be 1.3 microM Mg2+ as 0.51 and 0.29 microM, respectively. The maximum intracellular iron and manganese levels were decreased significantly with increasing Mg2+ concentration in the culture medium and were increased depending upon the incubation period. However, intracellular zinc levels of these strains didn't change with Mg2+ concentration and incubation period.The maximum superoxide dismutase (MnSOD) activities of F. equiseti and F. acuminatum, related to increased intracellular manganese levels up to 1.6 microM Mg2+ in growth medium, were determined to be 78 and 110 IU/mg, respectively. CAT activity variations showed agreement with SOD activity and reached a maximum at 320 and 225 IU/mg under the same conditions. The minimum LPO levels of the Fusarium strains with the maximum MnSOD and CAT activities were determined as 1.2 and 0.9 nmol MDA/g., wet weight. The higher LPO level of F. equiseti grown at the same condition, in spite of 1.42-fold higher CAT activity due to the 1.41-fold lower SOD activity, as well as a 2.0-fold higher iron level, indicated increases in the generation of reactive oxygen species via the Fenton reaction. 相似文献
7.
Kalay E Sezgin O Chellappa V Mutlu M Morsy H Kayserili H Kreiger E Cansu A Toraman B Abdalla EM Aslan Y Pillai S Akarsu NA 《American journal of human genetics》2012,90(1):76-85
The autosomal-recessive form of popliteal pterygium syndrome, also known as Bartsocas-Papas syndrome, is a rare, but frequently lethal disorder characterized by marked popliteal pterygium associated with multiple congenital malformations. Using Affymetrix 250K SNP array genotyping and homozygosity mapping, we mapped this malformation syndrome to chromosomal region 21q22.3. Direct sequencing of RIPK4 (receptor-interacting serine/threonine kinase protein 4) showed a homozygous transversion (c.362T>A) that causes substitution of a conserved isoleucine with asparagine at amino acid position 121 (p.Ile121Asn) in the serine/threonine kinase domain of the protein. Additional pathogenic mutations-a homozygous transition (c.551C>T) that leads to a missense substitution (p.Thr184Ile) at a conserved position and a homozygous one base-pair insertion mutation (c.777_778insA) predicted to lead to a premature stop codon (p.Arg260ThrfsX14) within the kinase domain-were observed in two families. Molecular modeling of the kinase domain showed that both the Ile121 and Thr184 positions are critical for the protein's stability and kinase activity. Luciferase reporter assays also demonstrated that these mutations are critical for the catalytic activity of RIPK4. RIPK4 mediates activation of the nuclear factor-κB (NF-κB) signaling pathway and is required for keratinocyte differentiation and craniofacial and limb development. The phenotype of Ripk4(-/-) mice is consistent with the human phenotype presented herein. Additionally, the spectrum of malformations observed in the presented families is similar, but less severe than the conserved helix-loop-helix ubiquitous kinase (CHUK)-deficient human fetus phenotype; known as Cocoon syndrome; this similarity indicates that RIPK4 and CHUK might function via closely related pathways to promote keratinocyte differentiation and epithelial growth. 相似文献
8.
The variation of antioxidant defense system of Streptomyces sp. M4018 with respect to carbon sources
The effect of glycerol, glucose, and starch as carbon sources on the antioxidant defense system such as superoxide dismutase (SOD) and catalase (CAT) activities, pyruvate levels, and membrane lipid peroxidation (LPO) levels of Streptomyces sp. M4018, after isolation from the rhizosphere samples of Colutea arborescens and identification as a strain of S. hiroshimensis based on phenotypic and genotypic characteristics, were investigated. As an antioxidant defense enzyme, SOD activities increased up to 20 g/L of glycerol and 15 g/L of starch, while they showed negative correlation with glucose concentration. CAT activity variations of glycerol- and glucose-supplemented mediums showed significant positive correlations with the trend of SOD activities. However, CAT activity, in contrast to SOD, in Streptomyces sp. M4018 tended to decrease as the starch concentration increased. The production of pyruvate increased with respect to glycerol and starch up to 15 g/L, while it was positively correlated with glucose concentration. The highest pyruvate production was seen at 20 g/L glucose. Membrane LPO levels were negatively correlated with the activities of SOD and CAT enzymes, and the minimum LPO level was determined at 5 g/L of glucose, where SOD and CAT activities reached their maximum levels. Nevertheless, the higher SOD and CAT activities in a wider range of incubation period compared to the beginning by resulting in insignificant increases in membrane LPO levels showed the unusual antioxidant response capacities of the in Streptomyces sp. M4018 against the potentially deleterious effects of reactive oxygen species (ROS) for glycerol, glucose, and starch as carbon sources. 相似文献
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10.
Kapralov AA Kurnikov IV Vlasova II Belikova NA Tyurin VA Basova LV Zhao Q Tyurina YY Jiang J Bayir H Vladimirov YA Kagan VE 《Biochemistry》2007,46(49):14232-14244
Activation of peroxidase catalytic function of cytochrome c (cyt c) by anionic lipids is associated with destabilization of its tertiary structure. We studied effects of several anionic phospholipids on the protein structure by monitoring (1) Trp59 fluorescence, (2) Fe-S(Met80) absorbance at 695 nm, and (3) EPR of heme nitrosylation. Peroxidase activity was probed using several substrates and protein-derived radicals. Peroxidase activation of cyt c did not require complete protein unfolding or breakage of the Fe-S(Met80) bond. The activation energy of cyt c peroxidase changed in parallel with stability energies of structural regions of the protein probed spectroscopically. Cardiolipin (CL) and phosphatidic acid (PA) were most effective in inducing cyt c peroxidase activity. Phosphatidylserine (PS) and phosphatidylinositol bisphosphate (PIP2) displayed a significant but much weaker capacity to destabilize the protein and induce peroxidase activity. Phosphatidylinositol trisphosphate (PIP3) appeared to be a stronger inducer of cyt c structural changes than PIP2, indicating a role for the negatively charged extra phosphate group. Comparison of cyt c-deficient HeLa cells and mouse embryonic cells with those expressing a full complement of cyt c demonstrated the involvement of cyt c peroxidase activity in selective catalysis of peroxidation of CL, PS, and PI, which corresponded to the potency of these lipids in inducing cyt c's structural destabilization. 相似文献