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Substrate Construes the Copper and Nickel Ions Impacts on the Mushroom Tyrosinase Activities
Gheibi, N.,Saboury, A.A.,Haghbeen, K. Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.5
Mushroom tyrosinase (MT) structural changes in the presence of $Cu ^{2+}$ and $Ni ^{2+}$ were studied separately. Far-UV CD spectra of the incubated MT with the either of the metal ions indicated reduction of the well-ordered secondary structure of the enzyme. Increasing in the maximum fluorescence emission of anilinonaphthalene-8-sulfonic acid (ANS) was also revealing partial unfolding caused by the conformational changes in the tertiary structure of MT. Thermodynamic studies on the chemical denaturation of MT by dodecyl trimethylammonium bromide (DTAB) showed decrease in the stability of MT in the presence of $Cu ^{2+}$ or $Ni ^{2+}$ using their activation concentrations. Both activities of MT were also assessed in the presence of different concentrations of these ions, separately, with various monophenols and their corresponding diphenols. Kinetic studies revealed that cresolase activity on p-coumaric acid was boosted in the presence of either of the metal ions, but inhibited when phenol, L-tyrosine, or 4-[(4-methylphenyl)azo]-phenol was substrate. Similarly, catecholase activity on caffeic acid was enhanced in the presence of $Cu ^{2+}$ or $Ni ^{2+}$, but inhibited when catechol, L-DOPA, or 4-[(4-methylbenzo)azo]-1,2-benzenediol was substrate. Results of this study suggest that both cations make MT more fragile and less active. However, the effect of the substrate structure on the MT allosteric behavior can not be ignored.
Gheibi, N.,Saboury, A.A.,Sarreshtehdari, M. Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.5
Tyrosinase is a widespread enzyme with great promising capabilities. The Lineweaver-Burk plots of the catecholase reactions showed that the kinetics of mushroom tyrosinase (MT), activated by $Co^{2+}$ and $Zn^{2+}$ at different pHs (6, 7, 8 and 9) obeyed the non-essential activation mode. The binding of metal ions to the enzyme increases the maximum velocity of the enzyme due to an increase in the enzyme catalytic constant ($k_{cat}$). From the kinetic analysis, dissociation constants of the activator from the enzyme-metal ion complex ($K_a$) were obtained as $5{\times}10^4M^{-1}$ and $8.33{\times}10^3M^{-1}$ for $Co^{2+}$ and $Zn^{2+}$ at pH 9 and 6 respectively. The structural analysis of MT through circular dichroism (CD) and intensive fluorescence spectra revealed that the conformational stability of the enzyme in these pHs reaches its maximum value in the presence of each of the two metal ions.
Gheibi, Shahsanam The Korean Society of Pediatric Gastroenterology 2013 Pediatric gastroenterology, hepatology & nutrition Vol.16 No.4
Association between celiac disease and intussusception has been reported in adult. Although intussusception is common in children, it rarely has been reported in association with celiac disease. Two children, 5 and 7 years old, with celiac disease are reported here, whose initial presentation was intussusception prior to investigation for concomitant failure to thrive. They presented with acute and severe abdominal distention with vomiting, and donuts and pseudo- kidney appearance in abdominal ultrasonography. One patient's intussusception had reducted spontaneously, however the other had required surgery. In investigation for concomitant failure to thrive, tissue transglutaminase levels were very high and duodenal biopsies revealed celiac disease. Thus celiac testing is recommended in children with intussusception and growth failure.
N. Gheibi,A. A. Saboury,M. Sarreshtehdari 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.5
Tyrosinase is a widespread enzyme with great promising capabilities. The Lineweaver-Burk plots of the catecholase reactions showed that the kinetics of mushroom tyrosinase (MT), activated by Co^(2+) and Zn^(2+) at different pHs (6, 7, 8 and 9) obeyed the non-essential activation mode. The binding of metal ions to the enzyme increases the maximum velocity of the enzyme due to an increase in the enzyme catalytic constant (k_(cat)). From the kinetic analysis, dissociation constants of the activator from the enzyme-metal ion complex (K_a) were obtained as 5 × 10^4 M^−1 and 8.33 × 10^3 M^−1 for Co^2+ and Zn^2+ at pH 9 and 6 respectively. The structural analysis of MT through circular dichroism (CD) and intensive fluorescence spectra revealed that the conformational stability of the enzyme in these pHs reaches its maximum value in the presence of each of the two metal ions.
Shahsanam Gheibi 대한소아소화기영양학회 2013 Pediatric gastroenterology, hepatology & nutrition Vol.16 No.4
Association between celiac disease and intussusception has been reported in adult. Although intussusception is com-mon in children, it rarely has been reported in association with celiac disease. Two children, 5 and 7 years old, with celiac disease are reported here, whose initial presentation was intussusception prior to investigation for concomitant failure to thrive. They presented with acute and severe abdominal distention with vomiting, and donuts and pseu-do-kidney appearance in abdominal ultrasonography. One patient’s intussusception had reducted spontaneously, however the other had required surgery. In investigation for concomitant failure to thrive, tissue transglutaminase levels were very high and duodenal biopsies revealed celiac disease. Thus celiac testing is recommended in children with intussusception and growth failure.
The Impact of Abuse on the Quality of Life of the Elderly: A Population-based Survey in Iran
Honarvar, Behnam,Gheibi, Zahra,Asadollahi, Abdolrahim,Bahadori, Farzaneh,Khaksar, Elahe,Faradonbeh, Maryam Rabiey,Farjami, Mohammad The Korean Society for Preventive Medicine 2020 Journal of Preventive Medicine and Public Health Vol.53 No.2
Objectives: The quality of life (QoL) of the elderly and elder abuse are growing public health concerns. This study aimed to evaluate the prevalence of abuse and the association between QoL and abuse in older adults. Methods: Multistage random cluster sampling, along with valid QoL (LEIPAD: LEIden, the Netherlands; PADua, Italy; Helsinki, Finland) and abuse questionnaires, were used to assess QoL and elder abuse. Path analysis was performed using Mplus. SPSS and AMOS were used for the other analyses. Results: A total of 386 elderly individuals with a mean age of 68.00±6.10 years were interviewed, of whom 200 (51.8%), 289 (74.9%), and 376 (97.4%) were women, educated, and married, respectively. Moreover, 167 (43.2%) had low-to-moderate QoL, and 108 (27.9%) had experienced a moderate level of abuse. QoL and abuse were inversely associated (r=-0.253), with men (β=-0.24) more affected than women (β=-0.21). Musculoskeletal disorders were also strong determinants of QoL in the elderly. QoL was strongly associated with emotional abuse, while abuse was highly related to the social component of QoL. Furthermore, emotional abuse was the type of abuse most significantly associated with the self-care, depression/anxiety, cognitive, and social components of QoL. Sexual abuse, violation of personal rights, and neglect were the main determinants of the physical functioning, life satisfaction, and sexual domains of QoL, respectively. Conclusions: Nearly half of the elderly individuals lacked a high QoL, and at least one-fourth had experienced some form of abuse. Elder abuse was correlated inversely with QoL. Therefore, preventive interventions are recommended to decrease elder abuse in the family, community, and other settings.
Jokar, Fereshte,Mahabadi, Javad Amini,Salimian, Morteza,Taherian, Aliakbar,Hayat, Seyyed Mohammad Gheibi,Sahebkar, Amirhossein,Atlasi, Mohammad Ali KOREAN PHARMACOPUNCTURE INSTITUTE 2019 Journal of pharmacopuncture Vol.22 No.1
Background: Breast cancer is a complex, heterogeneous disease and one of the most common malignancies in women worldwide. The efficacy of chemotherapy as an important breast cancer treatment option has been severely limited because of the inherent or acquired resistance of cancer cells. The molecular chaperone heat shock protein 90 (HSP90) upregulated in response to cellular stress is required for functions such as conformational maturation, activation and stability in more than 200 client proteins, mostly of the signaling type. In this study, the expression of HSP90 isoforms including $HSP90{\alpha}$ and $HSP90{\beta}$ in breast cancer cell lines before and after treatment with doxorubicin (DOX) was assessed. Material and Methods: The cell cytotoxicity of DOX in MDA-MB-231 and MCF-7 cell lines was determined using the MTT assay. immunofluorescence and western blotting techniques were used to determine the expression of $HSP90{\beta}$ in the cell lines before and after DOX treatment. Immunofluorescence was also conducted to ascertain the expression of $HSP90{\alpha}$. Results: The MTT assay results showed that the MDA-MB-231 cells ($IC_{50}=14.521{\mu}M$) were more sensitive than the MCF-7 cells ($IC_{50}=16.3315{\mu}M$) to DOX. The immunofluorescence results indicated that the expression of $HSP90{\alpha}$ in both cell lines decreased after exposure to DOX. The western blot and immunofluorescence analyses showed that $HSP90{\beta}$ expression decreased in the MCF-7 cells but increased in the MDA-MB-231 cells after DOX treatment. Conclusion: The obtained results suggested that $HSP90{\alpha}$ and $HSP90{\beta}$ expression levels were reduced in the MCF-7 cells after exposure to DOX. In the MDA-MB-231 cells, $HSP90{\alpha}$ expression was reduced while $HSP90{\beta}$ was found to be overexpressed following DOX treatment.