Natural Products Chemistry and Pharmacognosy Commons^™

Jatropha Tanjorensis A Flora Of Southeast Nigeria: Isolation And Characterization Of Naringenin And Validation Of Bio-Enhanced Synergistical Activity Of Α- Tocopherol Toward Clinical Isolates Of Resistant Bacterial, Ikechukwu Kingsley Ijoma, Vincent Ishmael Egbulefu Ajiwe

Makara Journal of Science

Jatropha tanjorensis is among the rich floras of Southeast Nigeria and used by ethnic people to treat infections and manage health conditions. Ethnomedicine has long been employed in the treatment of ailments caused by bacterial pathogens. Studies showed that the incorporation of synthetic α-tocopherol to an antibacterial agent improves its activity. However, knowledge about the antibacterial-enhanced activity of plant-based α-tocopherols, especially those isolated from Jatropha tanjorensis, is limited because of the different bioactivities of synthetic and natural α-tocopherols. To determine the phytochemicals in J. tanjorensis, we carried out the structural elucidation of its leaf extracts. Naringenin and α-tocopherol …

Biowill - Characterising Willow Bark Bio-Actives For Skin Therapies, Arnold Marisa

ORBioM (Open Research BioSciences Meeting)

Willow bark is considered as a disposable by-product when processing willow for biomass. Willow (Salix) is known to contain high value bioactive compounds which include salicin and its derivatives, and other phytochemicals of interest such as polyphenols and flavonoids. The plant is historically known as the primary source of salicylates to which the well-known drug aspirin is derived from. The work forms part of the Interreg project BioWILL, which is focused on integrated “Zero Waste” biorefinery utilising all fractions of willow feedstock for the production of biochemicals and renewable energy. This project aims to investigate the crude and …

Integration Of Medicinal Fungi Into The Heber W. Youngken Jr. Medicinal Garden, Anthony Makashov

Senior Honors Projects

The Heber W. Youngken Jr. Medicinal Garden is a one-of-a-kind resource that houses close to 300 medicinal plants and is filled to the brim with educational opportunities. For the College of Pharmacy, this garden has been the centerpiece of many classes taught here at the University of Rhode Island and has roots as a physical teaching space. While the garden contains a plethora of plant species, medicinal fungi have yet to have been included in the garden, despite their relevance as both sources of pharmaceutical drug discovery and as natural products with inherent physiological benefits themselves. The purpose of my …

A Quantitative Analysis Of The Efficacy Of Various Essential Oils Against The Sars Cov-2 Virus, Elizabeth Wagstaff, Chandrelyn Kraczek, Jack Brandon Lopez

Annual Research Symposium

A poster presentation and abstract for the Roseman Symposium. The project focuses on testing 3 essential oil blends and two disinfectants containing an essential oil blend against SARS CoV-2 in response to the COVID-19 pandemic. The project procedure involves plaque assays, disinfection, and neutralization techniques.

The Benefits Of Astaxanthin To Improve Pain Relief In Patients With Painful Diabetic Neuropathy: An Open-Label, Randomized Controlled Trial, Rizaldy Taslim Pinzon, Mary Rose Angelina Budi Harsana

Pharmaceutical Sciences and Research

Treatment of diabetic neuropathy is still carried out by providing symptomatic therapy, which only improves ± 50% of the total symptoms felt by patients, but does not tackle the underlying causes of the disease. Astaxanthin is a potent antioxidant, anti-inflammatory, and anti-diabetic carotenoid that could be an additional treatment option. We aimed to measure the effectiveness of administering astaxanthin as an additional therapy to improve the impact of pain and discomfort experienced daily by diabetes mellitus patients with painful diabetic neuropathy. We conducted a randomized experimental study with an open label design of 36 patients who had been diagnosed with …

Comparative Analytical Study Of Phytochemicals In Selected Antidiabetic Medicinal Plant Seeds In Sri Lanka, Gowri Rajkumar, Mihiri Rangika Jayasinghe, Vinotha Sanmugarajah

Pharmaceutical Sciences and Research

Medicinal plants are universally used in the management of various diseases in different medical practices. A varied diversity of compounds extracted from plants may show anticancer, antibacterial, and antidiabetic activities. Comparative laboratory studies and scientific approach of efficacy related to phytochemicals found in medicinal plants in Sri Lanka have not been reported yet. This study aims to evaluate the phytochemicals in selected four different plant seeds such as Syzygium cumini (L.) Skeels, Brassica alba (L.) Rabenh, Trigonella foenum-graecum L. and Nigella sativa L., which are used in the management of diabetes mellitus in Sri Lanka. The ethanol extracts of …

An Investigation Into The Use Of An Herbal Labor Induction Tincture Containing Black Cohosh, Cramp Bark, Partridgeberry, And Motherwort On Contractile Responses Produced From Isolated Strips Of Mouse Uterine Tissues, Clayton Neuenschwander, Katrina Wu, Teresa F. Degolier

Biological Sciences Faculty Publications

Introduction: Alternative solutions in the form of herbal remedies meant to ease or expedite the process of labor have often been pursued and administered but have seldom been quantitatively tested for efficacy. Published research has shown some validation for some commonly used herbs such as blue cohosh (Caulophyllum thalictroides), red raspberry (Rubus idaeus), castor bean (Ricinus communis) and evening primrose (Oenothera biennis) on isolated mouse uterine strips. Methods: This study tested an array of herbs used by midwives in a labor induction tincture, which included black cohosh (Actaea racemosa), cramp bark (Viburnum opulus), partridgeberry (Mitchella repens), and motherwort (Leonurus cardiaca). …

Complexation Of Glycoalkaloid Α- Tomatine With Sterols And Its Potential Application As An Anti-Cancer Drug, Bishal Nepal

Dissertations

Glycoalkaloids (GAs) are secondary metabolites found mostly in higher plant species and some marine invertebrates. They are known to form complexes with 3β-hydroxy sterols such as cholesterol causing membrane disruption. So far the visual evidence showcasing the complexes formed between glycoalkaloids and sterols has been mainly restricted to some earlier studies using Brewster angle microscopy. This study aimed to develop a method for topographic and morphological analysis of sterol-glycoalkaloid complexes. Langmuir-Blodgett (LB) transfer of monolayers comprising of glycoalkaloid tomatine, sterols, and lipids in varying molar ratios onto mica followed by AFM examination was performed. The AFM method used required minimal …

Novel Uplc-Ms/Ms Method For Standardization Of Niazimicin Content In Edible Seeds And Leaves Of Moringa Oleifera Lam., Eman M. Abdelsayed, Amira Abdel Motaal, Rasha S. Hanafi

Journal of Food and Drug Analysis

Moringa oleifera (MO) is a highly nutritious plant, whose leaves and seed pods are consumed in Africa, Asia, sub-Himalayan regions and South America. A novel ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the standardization of the bioactive thiocarbamate compound from MO, niazimicin (NZ) in seeds and leaves, is developed, optimized and validated according to the International Conference on Harmonization (ICH) guidelines, using desipramine as the internal standard. Multiple reaction monitoring detection of transitions 358.05>106.86 and 266.38 > 193.04 with collision energy of 25V and 40V, respectively were used. A gradient was optimized at 35-55%B …

The Bioactivities Of Resveratrol And Its Naturally Occurring Derivatives On Skin, Ming-Hsien Lin, Chi-Feng Hung, Hsin-Ching Sung, Shih-Chun Yang, Huang-Ping Yu, Jia-You Fang

Journal of Food and Drug Analysis

Resveratrol has been extensively reported as a potential compound to treat some skin disorders, including skin cancer, photoaging, allergy, dermatitis, melanogenesis, and microbial infection. There has been an increasing interest in the discovery of cosmetic application using resveratrol as the active ingredient because of its anti-aging and skin lightening activities. The naturally occurring derivatives of resveratrol also exert a beneficial effect on the skin. There are four groups of resveratrol derivatives, including hydroxylated compounds, methoxylated compounds, glycosides, and oligomers. The major mechanism of resveratrol and its derivatives for attenuating cutaneous neoplasia, photoaging and inflammation, are related with its antioxidative activity …

Evaluation Of The Anticancer Potential Of Alchemilla Vulgaris Extract Against Human Neuroblastoma Cells, Yomna Moqidem

Theses and Dissertations

Neuroblastoma is one of the most challenging pediatric tumors that present heterogeneity in prognosis and survival despite intensive treatment protocols. Therefore, there is an urge to develop novel and more potent anticancer drugs. Medicinal plants have recently gained worldwide attention due to their variable activities, wide availability, and cost-efficiency. Accordingly, this study attempted to identify novel plant extracts that could show potential anticancer properties against neuroblastoma. In this study, Alchemilla vulgaris (A.vulgaris) ethyl acetate extract was prepared and evaluated for its anticancer potential against SH-SY5Y Human neuroblastoma cell line. The Phenolic content of the prepared extract was characterized …

Structural Characterization And In Vitro Antiproliferative Activity Of Non-Specific Lipid Transfer Protein 1 (Nsltp1) From Fennel (Foeniculum Vulgare) Seeds, Mekdes Megeressa

Pharmaceutical Sciences (PhD) Dissertations

Non-specific lipid transfer proteins (nsLTPs) are cationic proteins involved in intracellular lipid shuttling, in growth and reproduction, as well as in defense against pathogenic microbes. Even though the primary and spatial structures of some nsLTPs from different plants indicate their similar features, they exhibit distinct lipid-binding specificities signifying their various biological roles that dictate further structural study. The present study determined the complete amino acid sequence, in silico 3D structure modeling, and in vitro antiproliferative activity of nsLTP1 from fennel (Foeniculum vulgare) seeds.

Fennel is a member of the family Umbelliferae (Apiaceae) native to southern Europe and the …

Science-Based Regulation Of Pharmacological Substances In Competition Horses, Jacob Machin

Theses and Dissertations--Toxicology and Cancer Biology

Current testing methodologies within equine forensic toxicology focus on arbitrary thresholds and zero-tolerance policy. Modern analytical chemistry’s limits of detection are low enough that oftentimes femtogram-per-milliliter amounts of a substance can readily be identified in both blood and urine of a horse. For most pharmacologically relevant compounds, these concentrations have no relevance to pharmacological effect. It is therefore crucial that testing methodologies to determine appropriate thresholds and cut-offs be developed that are driven by biological activity rather than arbitrary limits of detection. This dissertation looks to address this by suggesting a system of calculated Effective Plasma Concentrations by which a …

Structural Characterization And In Vitro Lipid Binding Studies Of Non-Specific Lipid Transfer Protein 1 (Nsltp1) From Fennel (Foeniculum Vulgare) Seeds, Mekdes Megeressa, Bushra Siraj, Shamshad Zarina, Aftab Ahmed

Pharmacy Faculty Articles and Research

Non-specific lipid transfer proteins (nsLTPs) are cationic proteins involved in intracellular lipid shuttling in growth and reproduction, as well as in defense against pathogenic microbes. Even though the primary and spatial structures of some nsLTPs from different plants indicate their similar features, they exhibit distinct lipid-binding specificities signifying their various biological roles that dictate further structural study. The present study determined the complete amino acid sequence, in silico 3D structure modeling, and the antiproliferative activity of nsLTP1 from fennel (Foeniculum vulgare) seeds. Fennel is a member of the family Umbelliferae (Apiaceae) native to southern Europe and the Mediterranean …

Effect Of Cannabidiol And ∆9-Tetrahydrocannabinol Concentration On Breast Cancer Cell Viability, Dorothy Achiaa Agyemang

Ursidae: The Undergraduate Research Journal at the University of Northern Colorado

-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are phytocannabinoids that have a potential impact in cancer treatments. Studies have shown that certain cannabinoids cause cancer cells to die, but only with selective concentrations, which have not been well documented. The first study of this thesis was to determine the exact concentration of CBD and THC needed to kill human MCF-7 breast cancer cells rather than create mass multiplication leading to more growth of the cancer. To conduct this experiment, cell culture was performed with a MCF-7 breast cancer cell line. The treatment groups were treated with CBD or THC at varying concentrations …

Impacts Of Embryonic Exposure To Cannabidiol Or ∆9-Tetrahydrocannabinol On Zebrafish (Danio Rerio) Frailty In F0 And F1 Generations, Anika Faruque

Honors Theses

Exposure to cannabinoids during critical development periods has increased with epileptic children being commonly prescribed CBD for seizures and pregnant women taking it recreationally. Many studies have been done on the possible benefits and drawbacks of cannabinoid exposure on the human brain, but not much is known about how it can affect the developing brain long-term. To see the potential adverse effects of cannabinoid exposure during critical stages of development and discover potential developmental origins of disease in consuming cannabinoids during embryogenesis, zebrafish embryos (6-96 hours post fertilization) were exposed to varying concentrations of CBD (0.02, 0.1, 0.5 µM), THC …

Pseudomonas And Bacillus As Potential Sources Of Novel Antibiotics, Cory Jayne, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

With an increase in antibiotic resistance within the medical field the need for novel antibiotics is evident. Through collaboration with the Tiny Earth Project Initiative, we hope to find novel antibiotics through bacteria found in soil. We were able to successfully isolate two microbes that showed broad spectrum antibiotics against both Staphylococcus epidermis and Bacillus subtilis. Through further exploration and collaboration with the Tiny Earth Project Initiative, we might be able to discover novel antibiotics.

Antiproliferative And Apoptotic Effects Of Proteins From Black Seeds (Nigella Sativa) On Human Breast Mcf-7 Cancer Cell Line, Yamna Khursid, Basir Syed, Shabana U. Simjee, Obaid Beg, Aftab Ahmed

Pharmacy Faculty Articles and Research

Background

Nigella sativa (NS), a member of family Ranunculaceae is commonly known as black seed or kalonji. It has been well studied for its therapeutic role in various diseases, particularly cancer. Literature is full of bioactive compounds from NS seed. However, fewer studies have been reported on the pharmacological activity of proteins. The current study was designed to evaluate the anticancer property of NS seed proteins on the MCF-7 cell line.

Methods

NS seed extract was prepared in phosphate-buffered saline (PBS), and proteins were precipitated using 80% ammonium sulfate. The crude seed proteins were partially purified using gel filtration …

Correlating The Physicochemical Properties Of Magnesium Stearate With Tablet Dissolution And Lubrication, Julie L. Calahan

Theses and Dissertations--Pharmacy

Magnesium stearate (MgSt) is the most commonly used pharmaceutical excipient and is present in over half the tablet formulations on the market. In spite of its popularity as an effective lubricant, it has been repeatedly recognized that there is significant variability between MgSt samples, which can cause inconsistent lubrication between batches of MgSt. The hypothesis of this research is that the batch-to-batch variability in tablet lubrication and dissolution observed in tablet formulations containing different MgSt samples can be correlated with differences in MgSt physicochemical properties (fatty acid salt composition, crystal hydrate form, particle size and surface area). Developing correlations between …

Variability In Antibacterial Activity In The Caribbean Sponge Amphimedon Compressa, Mackenzie Reilly

Honors Theses

Coral reefs are essential ecosystems that provide an abundance of natural resources. Sponges, common reef inhabitants, produce a diversity of secondary metabolites that are known to serve as chemical defenses. Secondary metabolites often have ecological functions, such as antipredator and antibacterial activities. I studied the common Caribbean sponge species, Amphimedon compressa, which is known to be chemically defended. Samples were collected from three sites in Belize, two sites in Grand Cayman, and three sites in St. Croix, U.S. Virgin Islands. To determine whether antibacterial activity varied across broad or local geographic scales, sponge extracts were tested against four bacterial strains …

Phytochemical Screening, In Vitro Antimalarial Activity And Genetic Diversity Of Selected Asteraceae Medicinal Plants Indigenous To Thailand, Desy Liana

Chulalongkorn University Theses and Dissertations (Chula ETD)

The emergence of artemisinin resistance leaded the effort to find the new antimalarial drug or artemisinin activity booster. Due to the chance that secondary metabolites can be evolutionary conserved, combining phylogeny with ethnobotanical data for screening antimalarial activity may be helpful to predict bioactivity and minimize the expenditure and time for laboratory research. The aimed of this study is screening the antimalarial activity, phytochemicals and genetic diversity of selected Asteraceae medicinal plants generated by combinatorial phylogeny and ethnobotanical data. 733 medicinal plants were obtained from literature search however only 340 taxa were met the inclusion and exclusion criteria hence these …

Which Factors Influence The Usage And Perceptions Of Medicinal Plants In Kizanda Village (Lushoto District) And Ushongo Village (Tanga District)?, Callie Smith

Independent Study Project (ISP) Collection

The objective of this study was to compare and examine which factors impact usage and perceptions of traditional medicine in Ushongo Mtoni and Kizanda villages. More specifically, this study aimed to gain an understanding of the usages, with a specific focus on gendered usages of medicinal plants in Kizanda village and Ushongo Mtoni village and to try to examine the differences in perceptions towards traditional medicine usage in Kizanda and Ushongo. Additionally, this study aimed to determine if there are any major themes that are constant with medicinal plants in both Ushongo and Kizanda. In order to conduct this study …

An Evaluation Of The Medicinal Plants Of Andros Island, Bahamas, Vivian Pedrozo

Theses and Dissertations

The earliest civilizations have been using plants as their foundation for healing and medicinal traditions for thousands of years. The use of plant medicinals, more commonly known as “bush medicine” on Andros Island, has been rapidly decreasing due an increased presence of western medicine and increased population pressures from urbanization that are threatening local biodiversity hotspots. Ethnobotany is not only important from a conservation standpoint but is also used to preserve traditional knowledge of herbal medicinals and applications, the people of Andros continue to rely on bush medicine, mainly in the form of teas to help manage health related problems. …

Purification And Characterization Of A Nonspecific Lipid Transfer Protein 1 (Nsltp1) From Ajwain (Trachyspermum Ammi) Seeds, Meshal Nazeer, Humera Waheed, Maria Saeed, Saman Yousuf Ali, M. Iqbal Choudhary, Zaheer Ul-Haq, Aftab Ahmed

Pharmacy Faculty Articles and Research

Ajwain (Trachyspermum ammi) belongs to the family Umbelliferae, is commonly used in traditional, and folk medicine due to its carminative, stimulant, antiseptic, diuretic, antihypertensive, and hepatoprotective activities. Non-specific lipid transfer proteins (nsLTPs) reported from various plants are known to be involved in transferring lipids between membranes and in plants defense response. Here, we describe the complete primary structure of a monomeric non-specific lipid transfer protein 1 (nsLTP1), with molecular weight of 9.66 kDa, from ajwain seeds. The nsLTP1 has been purified by combination of chromatographic techniques, and further characterized by mass spectrometry, and Edman degradation. The ajwain nsLTP1 …

The Value Of Universally Available Raw Nmr Data For Transparency, Reproducibility, And Integrity In Natural Product Research., James B. Mcalpine, Shao-Nong Chen, Andrei Kutateladze, John B. Macmillan, Giovanni Appendino, Andersson Barison, Mehdi A. Beniddir, Maique W. Biavatti, Stefan Bluml, Asmaa Boufridi, Mark S. Butler, Robert J. Capon, Young H. Choi, David Coppage, Phillip Crews, Michael T. Crimmins, Marie Csete, Pradeep Dewapriya, Joseph M. Egan, Mary J. Garson, Grégory Genta-Jouve, William H Gerwick, Harald Gross, Mary Kay Harper, Precilia Hermanto, James M. Hook, Luke Hunter, Damien Jeannerat, Nai-Yun Ji, Tyler A. Johnson, David G. I. Kingston, Hiroyuki Koshino, Hsiau-Wei Lee, Guy Lewin, Jie Li, Roger G Linington, Miaomiao Liu, Kerry L Mcphail, Tadeusz F Molinski, Bradley S Moore, Joo-Won Nam, Ram P Neupane, Matthias Niemitz, Jean-Marc Nuzillard, Nicholas H Oberlies, Fernanda M M Ocampos, Guohui Pan, Ronald J Quinn, D Sai Reddy, Jean-Hugues Renault, José Rivera-Chávez, Wolfgang Robien, Carla M Saunders, Thomas J Schmidt, Christoph Seger, Ben Shen, Christoph Steinbeck, Hermann Stuppner, Sonja Sturm, Orazio Taglialatela-Scafati, Dean J Tantillo, Robert Verpoorte, Bin-Gui Wang, Craig M Williams, Philip G Williams, Julien Wist, Jian-Min Yue, Chen Zhang, Zhengren Xu, Charlotte Simmler, David C Lankin, Jonathan Bisson, Guido F Pauli

Natural Sciences and Mathematics | Faculty Scholarship

With contributions from the global natural product (NP) research community, and continuing the Raw Data Initiative, this review collects a comprehensive demonstration of the immense scientific value of disseminating raw nuclear magnetic resonance (NMR) data, independently of, and in parallel with, classical publishing outlets. A comprehensive compilation of historic to present-day cases as well as contemporary and future applications show that addressing the urgent need for a repository of publicly accessible raw NMR data has the potential to transform natural products (NPs) and associated fields of chemical and biomedical research. The call for advancing open sharing mechanisms for raw data …

Comparative Characteristics Of Antibacterial Activity Of Plants Growing In The Central Part Of The Republic Of Tajikistan., Saidbeg Satorov, F. Mirzoeva, Sh. Satorov, M. Vakhidova, Vyacheslav Dushenkov

Publications and Research

Objective: To evaluate the spectrum of antibacterial activity of plants growing in the central part of the Republic of Tajikistan.
Methods: The antibacterial properties of 18 plant species from the 14 families were studied. The extract samples on dry filter discs were prepared according to the method developed at Rutgers University. Screens-to-Nature (STN) and disc diffusion (DD) methods were used to assess antimicrobial properties of the extracts. The antimicrobial activity of plant extracts was determined against four types of pathogenic standard museum strains of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, as well as …

Development Of Mithramycin Analogues With Improved Efficacy And Reduced Toxicity For Treatment Of Ets-Dependent Tumors In Ewing Sarcoma And Prostate Cancer, Joseph Michael Eckenrode

Theses and Dissertations--Pharmacy

Introduction: Genetic rearrangements in Ewing sarcoma, prostate, and leukemia cells result in activation of oncogenic ETS transcription factor fusions. Mithramycin (MTM) has been identified as an inhibitor of EWS-FLI1 transcription factor, a gene fusion product responsible for oncogenesis in Ewing sarcoma. Despite preclinical success, a phase I/II clinical trial testing MTM therapy in refractory Ewing sarcoma was terminated. Liver and blood toxicities resulted in dose de-escalation and sub-therapeutic exposures. However, the promise of selectively targeting oncogenic ETS transcription factors like EWS-FLI1 prompted us to undertake the discovery of more selective, less toxic analogues of MTM. MTM is a potent inhibitor …

Toward An Enzyme-Coupled, Bioorthogonal Platform For Methyltransferases: Probing The Specificity Of Methionine Adenosyltransferases, Tyler D. Huber

Theses and Dissertations--Pharmacy

Methyl group transfer from S-adenosyl-l-methionine (AdoMet) to various substrates including DNA, proteins, and natural products (NPs), is accomplished by methyltransferases (MTs). Analogs of AdoMet, bearing an alternative S-alkyl group can be exploited, in the context of an array of wild-type MT-catalyzed reactions, to differentially alkylate DNA, proteins, and NPs. This technology provides a means to elucidate MT targets by the MT-mediated installation of chemoselective handles from AdoMet analogs to biologically relevant molecules and affords researchers a fresh route to diversify NP scaffolds by permitting the differential alkylation of chemical sites vulnerable to NP MTs that are unreactive to …

Characterization Of G-Protein Coupled Receptors In Pain, Depression And Anxiety, Neil Lax

Electronic Theses and Dissertations

Chronic pain and major depressive disorder are widespread conditions in the world. Interestingly, these conditions often occur comorbidly, with each individual disease amplifying the symptoms of the other. A significant amount of preclinical research in pain and depression focuses on G-protein coupled receptors (GPCRs), implying that GPCRs may be useful in treating this comorbidity. Our efforts have sought to characterize several poorly understood GPCRs, including the serotonin receptor subtypes 2C and 7 (5-HT2CR and 5-HT7R) and metabotropic glutamate receptor 5 (mGluR5), along with more well-known GPCRs such as the mu opioid receptor (MOR), and the role that they play in …

A V-To-F Substitution In Sk2 Channels Causes Ca2+ Hypersensitivity And Improves Locomotion In A C. Elegans Als Model, Young-Woo Nam, Sabia N. Baskoylu, Dimitris Gazgalis, Razan Orfali, Meng Cui, Anne C. Hart, Miao Zhang

Pharmacy Faculty Articles and Research

Small-conductance Ca2+-activated K+ (SK) channels mediate medium afterhyperpolarization in the neurons and play a key role in the regulation of neuronal excitability. SK channels are potential drug targets for ataxia and Amyotrophic Lateral Sclerosis (ALS). SK channels are activated exclusively by the Ca2+-bound calmodulin. Previously, we identified an intrinsically disordered fragment that is essential for the mechanical coupling between Ca2+/calmodulin binding and channel opening. Here, we report that substitution of a valine to phenylalanine (V407F) in the intrinsically disordered fragment caused a ~6 fold increase in the Ca2+ sensitivity of SK2-a channels. This substitution resulted in a novel interaction between …