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Full-Text Articles in Genetic Processes

Individual Longitudinal Changes In Dna-Methylome Identify Signatures Of Early-Life Adversity And Correlate With Later Outcome, Annabel K. Short, Ryan Weber, Noriko Kamei, Christina Wilcox Thai, Hina Arora, Ali Mortazavi, Hal S. Stern, Laura M. Glynn, Tallie Z. Baram May 2024

Individual Longitudinal Changes In Dna-Methylome Identify Signatures Of Early-Life Adversity And Correlate With Later Outcome, Annabel K. Short, Ryan Weber, Noriko Kamei, Christina Wilcox Thai, Hina Arora, Ali Mortazavi, Hal S. Stern, Laura M. Glynn, Tallie Z. Baram

Psychology Faculty Articles and Research

Adverse early-life experiences (ELA) affect a majority of the world's children. Whereas the enduring impact of ELA on cognitive and emotional health is established, there are no tools to predict vulnerability to ELA consequences in an individual child. Epigenetic markers including peripheral-cell DNA-methylation profiles may encode ELA and provide predictive outcome markers, yet the interindividual variance of the human genome and rapid changes in DNA methylation in childhood pose significant challenges. Hoping to mitigate these challenges we examined the relation of several ELA dimensions to DNA methylation changes and outcome using a within-subject longitudinal design and a high methylation-change threshold. …


Purification And Biochemical Characterization Of The Dna Binding Domain Of The Nitrogenase Transcriptional Activator Nifa From Gluconacetobacter Diazotrophicus, Heidi G. Standke, Lois Kim, Cedric P. Owens Oct 2023

Purification And Biochemical Characterization Of The Dna Binding Domain Of The Nitrogenase Transcriptional Activator Nifa From Gluconacetobacter Diazotrophicus, Heidi G. Standke, Lois Kim, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

NifA is a σ54 activator that turns on bacterial nitrogen fixation under reducing conditions and when fixed cellular nitrogen levels are low. The redox sensing mechanism in NifA is poorly understood. In α- and β-proteobacteria, redox sensing involves two pairs of Cys residues within and immediately following the protein’s central AAA+ domain. In this work, we examine if an additional Cys pair that is part of a C(X)5 C motif and located immediately upstream of the DNA binding domain of NifA from the α-proteobacterium Gluconacetobacter diazotrophicus (Gd) is involved in redox sensing. We hypothesize that the …


Structural Basis For The Simultaneous Recognition Of Nemo And Acceptor Ubiquitin By The Hoip Nzf1 Domain, Simin Rahighi, Mamta Iyer, Hamid Oveisi, Sammy Nasser, Vincent Duong Jul 2022

Structural Basis For The Simultaneous Recognition Of Nemo And Acceptor Ubiquitin By The Hoip Nzf1 Domain, Simin Rahighi, Mamta Iyer, Hamid Oveisi, Sammy Nasser, Vincent Duong

Pharmacy Faculty Articles and Research

Ubiquitination of NEMO by the linear ubiquitin chain assembly complex (LUBAC) is essential for activating the canonical NF-κB signaling pathway. While the NZF1 domain of the HOIP subunit of LUBAC recognizes the NEMO substrate, it is unclear how it cooperates with the catalytic domains in the ubiquitination process. Here, we report a crystal structure of NEMO in complex with HOIP NZF1 and linear diubiquitin chains, in which the two proteins bind to distinct sites on NEMO. Moreover, the NZF1 domain simultaneously interacts with NEMO and Ile44 surface of a proximal ubiquitin from a linear diubiquitin chain, where the C-term tail …


Synthesis And Evaluation Of Anti-Hiv Activity Of Mono- And Di-Substituted Phosphonamidate Conjugates Of Tenofovir, Aaminat Qureshi, Louise A. Ouattara, Naglaa Salem El-Sayed, Amita Verma, Gustavo F. Doncel, Muhammad Iqbal Choudhary, Hina Siddiqui, Keykavous Parang Jul 2022

Synthesis And Evaluation Of Anti-Hiv Activity Of Mono- And Di-Substituted Phosphonamidate Conjugates Of Tenofovir, Aaminat Qureshi, Louise A. Ouattara, Naglaa Salem El-Sayed, Amita Verma, Gustavo F. Doncel, Muhammad Iqbal Choudhary, Hina Siddiqui, Keykavous Parang

Pharmacy Faculty Articles and Research

The activity of nucleoside and nucleotide analogs as antiviral agents requires phosphorylation by endogenous enzymes. Phosphate-substituted analogs have low bioavailability due to the presence of ionizable negatively-charged groups. To circumvent these limitations, several prodrug approaches have been proposed. Herein, we hypothesized that the conjugation or combination of the lipophilic amide bond with nucleotide-based tenofovir (TFV) (1) could improve the anti-HIV activity. During the current study, the hydroxyl group of phosphonates in TFV was conjugated with the amino group of L-alanine, L-leucine, L-valine, and glycine amino acids and other long fatty ester hydrocarbon chains to synthesize 43 derivatives. Several …


Ciliary Extracellular Vesicles Are Distinct From The Cytosolic Extracellular Vesicles, Ashraf M. Mohieldin, Rajasekharreddy Pala, Richard Beuttler, James J. Moresco, John R. Yates Iii, Surya M. Nauli Apr 2021

Ciliary Extracellular Vesicles Are Distinct From The Cytosolic Extracellular Vesicles, Ashraf M. Mohieldin, Rajasekharreddy Pala, Richard Beuttler, James J. Moresco, John R. Yates Iii, Surya M. Nauli

Pharmacy Faculty Articles and Research

Extracellular vesicles (EVs) are cell‐derived membrane vesicles that are released into the extracellular space. EVs encapsulate key proteins and mediate intercellular signalling pathways. Recently, primary cilia have been shown to release EVs under fluid‐shear flow, but many proteins encapsulated in these vesicles have never been identified. Primary cilia are ubiquitous mechanosensory organelles that protrude from the apical surface of almost all human cells. Primary cilia also serve as compartments for signalling pathways, and their defects have been associated with a wide range of human genetic diseases called ciliopathies. To better understand the mechanism of ciliopathies, it is imperative to know …


Overcoming Barriers For Sirna Therapeutics: From Bench To Bedside, Muhammad Imran Sajid, Muhammad Moazzam, Shun Kato, Kayley Yeseom Cho, Rakesh Kumar Tiwari Oct 2020

Overcoming Barriers For Sirna Therapeutics: From Bench To Bedside, Muhammad Imran Sajid, Muhammad Moazzam, Shun Kato, Kayley Yeseom Cho, Rakesh Kumar Tiwari

Pharmacy Faculty Articles and Research

The RNA interference (RNAi) pathway possesses immense potential in silencing any gene in human cells. Small interfering RNA (siRNA) can efficiently trigger RNAi silencing of specific genes. FDA Approval of siRNA therapeutics in recent years garnered a new hope in siRNA therapeutics. However, their therapeutic use is limited by several challenges. siRNAs, being negatively charged, are membrane-impermeable and highly unstable in the systemic circulation. In this review, we have comprehensively discussed the extracellular barriers, including enzymatic degradation of siRNAs by serum endonucleases and RNAases, rapid renal clearance, membrane impermeability, and activation of the immune system. Besides, we have thoroughly described …


Effects Of Germline And Somatic Events In Candidate Brca-Like Genes On Breast-Tumor Signatures, Weston R. Bodily, Brian H. Shirts, Tom Walsh, Suleyman Gulsuner, Mary-Claire King, Alyssa Parker, Moom Roosan, Stephen R. Piccolo Sep 2020

Effects Of Germline And Somatic Events In Candidate Brca-Like Genes On Breast-Tumor Signatures, Weston R. Bodily, Brian H. Shirts, Tom Walsh, Suleyman Gulsuner, Mary-Claire King, Alyssa Parker, Moom Roosan, Stephen R. Piccolo

Pharmacy Faculty Articles and Research

Mutations in BRCA1 and BRCA2 cause deficiencies in homologous recombination repair (HR), resulting in repair of DNA double-strand breaks by the alternative non-homologous end-joining pathway, which is more error prone. HR deficiency of breast tumors is important because it is associated with better responses to platinum salt therapies and PARP inhibitors. Among other consequences of HR deficiency are characteristic somatic-mutation signatures and gene-expression patterns. The term “BRCA-like” (or “BRCAness”) describes tumors that harbor an HR defect but have no detectable germline mutation in BRCA1 or BRCA2. A better understanding of the genes and molecular events associated with tumors being …


The Project Talent Twin And Sibling Study: Zygosity And New Data Collection, Carol A. Prescott, Ellen E. Walters, Thalida Em Arpawong, Catalina Zavala, Tara L. Gruenewald, Margaret Gatz Feb 2020

The Project Talent Twin And Sibling Study: Zygosity And New Data Collection, Carol A. Prescott, Ellen E. Walters, Thalida Em Arpawong, Catalina Zavala, Tara L. Gruenewald, Margaret Gatz

Psychology Faculty Articles and Research

The Project Talent Twin and Sibling (PTTS) study includes 4481 multiples and their 522 nontwin siblings from 2233 families. The sample was drawn from Project Talent, a U.S. national longitudinal study of 377,000 individuals born 1942–1946, first assessed in 1960 and representative of U.S. students in secondary school (Grades 9–12). In addition to the twins and triplets, the 1960 dataset includes 84,000 siblings from 40,000 other families. This design is both genetically informative and unique in facilitating separation of the ‘common’ environment into three sources of variation: shared by all siblings within a family, specific to twin-pairs, and associated with …


A "Choose-Your-Own" Classroom-Based Activity That Promotes Scientific Inquiry About Rna Interference, Jeremy L. Hsu Dec 2019

A "Choose-Your-Own" Classroom-Based Activity That Promotes Scientific Inquiry About Rna Interference, Jeremy L. Hsu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

RNA interference (RNAi), the process that results in the degradation of a target gene’s mRNA, is a fundamental part of eukaryotic gene regulation and is also an important molecular technique that allows for experimental manipulation of gene expression without altering DNA sequences. Despite the importance of RNAi, there have been relatively few lecture-based activities designed to teach about the consequences of this process and counter common misconceptions. I present here an inquiry-based activity that is centered around a “choose your own experiment” design where students generate hypotheses and critically evaluate their ideas by choosing several simulated experiments. The activity presents …


A Systematic Comparison Of Lipopolymers For Sirna Delivery To Multiple Breast Cancer Cell Lines: In Vitro Studies, Hamidreza Montazeri Aliabadi, Remant Bahadur Kc, Emira Bousoik, Ashley Barbarino, Bindu Thapa, Melissa Coyle, Parvin Mahdipoor, Hasan Uludağ Nov 2019

A Systematic Comparison Of Lipopolymers For Sirna Delivery To Multiple Breast Cancer Cell Lines: In Vitro Studies, Hamidreza Montazeri Aliabadi, Remant Bahadur Kc, Emira Bousoik, Ashley Barbarino, Bindu Thapa, Melissa Coyle, Parvin Mahdipoor, Hasan Uludağ

Pharmacy Faculty Articles and Research

Small interfering RNA (siRNA) therapy is a promising approach for treatment of a wide range of cancers, including breast cancers that display variable phenotypic features. To explore the general utility of siRNA therapy to control aberrant expression of genes in breast cancer, we conducted a detailed analysis of siRNA delivery and silencing response in vitro in 6 separate breast cancer cell models (MDA-MB-231, MDA-MB-231-KRas-CRM, MCF-7, AU565, MDA-MB-435 and MDA-MB-468 cells). Using lipopolymers for siRNA complexation and delivery, we found a large variation in siRNA delivery efficiency depending on the specific lipopolymer used for siRNA complexation and delivery. Some lipopolymers were …


Integration Of Random Forest Classifiers And Deep Convolutional Neural Networks For Classification And Biomolecular Modeling Of Cancer Driver Mutations, Steve Agajanian, Odeyemi Oluyemi, Gennady M. Verkhivker Jun 2019

Integration Of Random Forest Classifiers And Deep Convolutional Neural Networks For Classification And Biomolecular Modeling Of Cancer Driver Mutations, Steve Agajanian, Odeyemi Oluyemi, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Development of machine learning solutions for prediction of functional and clinical significance of cancer driver genes and mutations are paramount in modern biomedical research and have gained a significant momentum in a recent decade. In this work, we integrate different machine learning approaches, including tree based methods, random forest and gradient boosted tree (GBT) classifiers along with deep convolutional neural networks (CNN) for prediction of cancer driver mutations in the genomic datasets. The feasibility of CNN in using raw nucleotide sequences for classification of cancer driver mutations was initially explored by employing label encoding, one hot encoding, and embedding to …


Fluorometholone Modulates Gene Expression Of Ocular Surface Mucins, Jonathan Taniguchi, Ajay Sharma Apr 2019

Fluorometholone Modulates Gene Expression Of Ocular Surface Mucins, Jonathan Taniguchi, Ajay Sharma

Pharmacy Faculty Articles and Research

Purpose

Mucins are vital to keep the ocular surface hydrated. Genes encoding for mucins contain a glucocorticoid response element. The purpose of this study was to evaluate the effect of fluorometholone, a glucocorticoid receptor agonist used in the management of dry eye, on the gene expression of conjunctival and corneal epithelial cell mucins.

Methods

Stratified cultures of human conjunctival and corneal epithelial cells were exposed to 25, 50 and 100 nM of fluorometholone alone or in presence of mifepristone, a glucocorticoid receptor antagonist. The mRNA was isolated from the cells and reverse transcribed to cDNA. The cDNA was used for …


Correcting Glucose-6-Phosphate Dehydrogenase Deficiency With A Small-Molecule Activator, Sunhee Hwang, Karen Mruk, Simin Rahighi, Andrew G. Raub, Che-Hong Chen, Lisa E. Dorn, Naoki Horikoshi, Soichi Wakatsuki, James K. Chen, Daria Mochly-Rosen Oct 2018

Correcting Glucose-6-Phosphate Dehydrogenase Deficiency With A Small-Molecule Activator, Sunhee Hwang, Karen Mruk, Simin Rahighi, Andrew G. Raub, Che-Hong Chen, Lisa E. Dorn, Naoki Horikoshi, Soichi Wakatsuki, James K. Chen, Daria Mochly-Rosen

Pharmacy Faculty Articles and Research

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, one of the most common human genetic enzymopathies, is caused by over 160 different point mutations and contributes to the severity of many acute and chronic diseases associated with oxidative stress, including hemolytic anemia and bilirubin-induced neurological damage particularly in newborns. As no medications are available to treat G6PD deficiency, here we seek to identify a small molecule that corrects it. Crystallographic study and mutagenesis analysis identify the structural and functional defect of one common mutant (Canton, R459L). Using high-throughput screening, we subsequently identify AG1, a small molecule that increases the activity of the wild-type, the …


Novel Combination Bmp7 And Hgf Gene Therapy Instigates Selective Myofibroblast Apoptosis And Reduces Corneal Haze In Vivo, Suneel Gupta, Michael K. Fink, Arkasubhra Ghosh, Ratnakar Tripathi, Prashant R. Sinha, Ajay Sharma, Nathan P. Hesemann, Shyam S. Chaurasia, Elizabeth A. Giuliano, Rajiv R. Mohan Feb 2018

Novel Combination Bmp7 And Hgf Gene Therapy Instigates Selective Myofibroblast Apoptosis And Reduces Corneal Haze In Vivo, Suneel Gupta, Michael K. Fink, Arkasubhra Ghosh, Ratnakar Tripathi, Prashant R. Sinha, Ajay Sharma, Nathan P. Hesemann, Shyam S. Chaurasia, Elizabeth A. Giuliano, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

PURPOSE. We tested the potential of bone morphogenic protein 7 (BMP7) and hepatocyte growth factor (HGF) combination gene therapy to treat preformed corneal fibrosis using established rabbit in vivo and human in vitro models.

METHODS. Eighteen New Zealand White rabbits were used. Corneal fibrosis was produced by alkali injury. Twenty-four hours after scar formation, cornea received topically either balanced salt solution (BSS; n ¼ 6), polyethylenimine-conjugated gold nanoparticle (PEI2-GNP)-naked plasmid (n ¼ 6) or PEI2-GNP plasmids expressing BMP7 and HGF genes (n ¼ 6). Donor human corneas were used to obtain primary human corneal fibroblasts and myofibroblasts for mechanistic studies. …


Activity Of Distinct Growth Factor Receptor Network Components In Breast Tumors Uncovers Two Biologically Relevant Subtypes, Moom Roosan, Shelley M. Macneil, David F. Jenkins, Gajendra Shrestha, Sydney R. Wyatt, Jasmine A. Mcquerry, Stephen R. Piccolo, Laura M. Heiser, Joe W. Gray, W. Evan Johnson, Andrea H. Bild Apr 2017

Activity Of Distinct Growth Factor Receptor Network Components In Breast Tumors Uncovers Two Biologically Relevant Subtypes, Moom Roosan, Shelley M. Macneil, David F. Jenkins, Gajendra Shrestha, Sydney R. Wyatt, Jasmine A. Mcquerry, Stephen R. Piccolo, Laura M. Heiser, Joe W. Gray, W. Evan Johnson, Andrea H. Bild

Pharmacy Faculty Articles and Research

Background
The growth factor receptor network (GFRN) plays a significant role in driving key oncogenic processes. However, assessment of global GFRN activity is challenging due to complex crosstalk among GFRN components, or pathways, and the inability to study complex signaling networks in patient tumors. Here, pathway-specific genomic signatures were used to interrogate GFRN activity in breast tumors and the consequent phenotypic impact of GRFN activity patterns.

Methods
Novel pathway signatures were generated in human primary mammary epithelial cells by overexpressing key genes from GFRN pathways (HER2, IGF1R, AKT1, EGFR, KRAS (G12V), RAF1, BAD). The pathway analysis toolkit Adaptive Signature Selection …


Regulation Of Polycystin-1 Function By Calmodulin Binding, Nicholas Doerr, Yidi Wang, Kevin R. Kipp, Guangyi Liu, Jesse J. Benza, Vladimir Pletnev, Tengis S. Pavlov, Alexander Staruschenko, Ashraf M. Mohieldin, Maki Takahashi, Surya M. Nauli, Thomas Weimbs Aug 2016

Regulation Of Polycystin-1 Function By Calmodulin Binding, Nicholas Doerr, Yidi Wang, Kevin R. Kipp, Guangyi Liu, Jesse J. Benza, Vladimir Pletnev, Tengis S. Pavlov, Alexander Staruschenko, Ashraf M. Mohieldin, Maki Takahashi, Surya M. Nauli, Thomas Weimbs

Pharmacy Faculty Articles and Research

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a common genetic disease that leads to progressive renal cyst growth and loss of renal function, and is caused by mutations in the genes encoding polycystin-1 (PC1) and polycystin-2 (PC2), respectively. The PC1/PC2 complex localizes to primary cilia and can act as a flow-dependent calcium channel in addition to numerous other signaling functions. The exact functions of the polycystins, their regulation and the purpose of the PC1/PC2 channel are still poorly understood. PC1 is an integral membrane protein with a large extracytoplasmic N-terminal domain and a short, ~200 amino acid C-terminal cytoplasmic tail. …


Il-15 Mediates Mitochondrial Activity Through A Ppar𝛿-Dependent-Ppar𝛼-Independent Mechanism In Skeletal Muscle Cells, Shantaé M. Thornton, James E. Krolopp, Marcia J. Abbott Jan 2016

Il-15 Mediates Mitochondrial Activity Through A Ppar𝛿-Dependent-Ppar𝛼-Independent Mechanism In Skeletal Muscle Cells, Shantaé M. Thornton, James E. Krolopp, Marcia J. Abbott

Health Sciences and Kinesiology Faculty Articles

Molecular mediators of metabolic processes, to increase energy expenditure, have become a focus for therapies of obesity. The discovery of cytokines secreted from the skeletal muscle (SKM), termed “myokines,” has garnered attention due to their positive effects on metabolic processes. Interleukin-15 (IL-15) is a myokine that has numerous positive metabolic effects and is linked to the PPAR family of mitochondrial regulators. Here, we aimed to determine the importance of PPAR𝛼 and/or PPAR𝛿 as targets of IL-15 signaling. C2C12 SKM cells were differentiated for 6 days and treated every other day with IL-15 (100 ng/mL), a PPAR𝛼 inhibitor (GW-6471), a PPAR𝛿 …


Targeting Cell Cycle Proteins In Breast Cancer Cells With Sirna By Using Lipid-Substituted Polyethylenimines, Manoj Parmar, Hamidreza Montazeri Aliabadi, Parvin Mahdipoor, Cezary Kucharski, Robert Maranchuk, Judith C. Hugh, Hasan Uludag Jan 2015

Targeting Cell Cycle Proteins In Breast Cancer Cells With Sirna By Using Lipid-Substituted Polyethylenimines, Manoj Parmar, Hamidreza Montazeri Aliabadi, Parvin Mahdipoor, Cezary Kucharski, Robert Maranchuk, Judith C. Hugh, Hasan Uludag

Pharmacy Faculty Articles and Research

The cell cycle proteins are key regulators of cell cycle progression whose de-regulation is one of the causes of breast cancer. RNA interference (RNAi) is an endogenous mechanism to regulate gene expression and it could serve as the basis of regulating aberrant proteins including cell cycle proteins. Since the delivery of small interfering RNA (siRNA) is a main barrier for implementation of RNAi therapy, we explored the potential of a non-viral delivery system, 2.0 kDa polyethylenimines substituted with linoleic acid and caprylic acid, for this purpose. Using a library of siRNAs against cell cycle proteins, we identified cell division cycle …


Cryptorchidism And Infertility In Rats With Targeted Disruption Of The Adamts16 Locus, Shakila Abdul-Majeed, Blair Mell, Surya M. Nauli, Bina Joe Jul 2014

Cryptorchidism And Infertility In Rats With Targeted Disruption Of The Adamts16 Locus, Shakila Abdul-Majeed, Blair Mell, Surya M. Nauli, Bina Joe

Pharmacy Faculty Articles and Research

A Disintegrin And Metalloproteinase with ThromboSpondin motifs16 (ADAMTS-16) is a member of a family of metalloproteinases. Using a novel zinc-finger nuclease based gene-edited rat model harboring a targeted mutation of the Adamts16 locus, we previously reported this gene to be linked to blood pressure regulation. Here we document our observation with this model that Adamts16 is essential for normal development of the testis. Absence of Adamts16 in the homozygous Adamts16(mutant) males resulted in cryptorchidism and male sterility. Heterozygous Adamts16(mutant) males were normal, indicating that this is a recessive trait. Testes of homozygous Adamts16(mutant) males were significantly smaller with significant histological …


Altered Self-Assembly And Apatite Binding Of Amelogenin Induced By N-Terminal Proline Mutation, Li Zhu, Vuk Uskoković, Thuan Le, Pamela Denbesten, Yulei Huang, Stefan Habelitz, Wu Li Jan 2011

Altered Self-Assembly And Apatite Binding Of Amelogenin Induced By N-Terminal Proline Mutation, Li Zhu, Vuk Uskoković, Thuan Le, Pamela Denbesten, Yulei Huang, Stefan Habelitz, Wu Li

Pharmacy Faculty Articles and Research

Objective—A single Pro-70 to Thr (p.P70T) mutation of amelogenin is known to result in hypomineralized amelogenesis imperfecta (AI). This study aims to test the hypothesis that the given mutation affects the self-assembly of amelogenin molecules and impairs their ability to conduct the growth of apatite crystals.

Design—Recombinant human full-length wild-type (rh174) and p.P70T mutated amelogenins were analyzed using dynamic light scattering (DLS), protein quantification assay and atomic force microscopy (AFM) before and after the binding of amelogenins to hydroxyapatite crystals. The crystal growth modulated by both amelogenins in a dynamic titration system was observed using AFM.

Results—As …


Hydrolysis Of Amelogenin By Matrix Metalloprotease-20 Accelerates Mineralization In Vitro, Vuk Uskoković, Feroz Khan, Haichuan Liu, Halina Ewa Witkowska, Li Zhu, Wu Li, Stefan Habelitz Jan 2011

Hydrolysis Of Amelogenin By Matrix Metalloprotease-20 Accelerates Mineralization In Vitro, Vuk Uskoković, Feroz Khan, Haichuan Liu, Halina Ewa Witkowska, Li Zhu, Wu Li, Stefan Habelitz

Pharmacy Faculty Articles and Research

In the following respects, tooth enamel is a unique tissue in the mammalian body: (a) it is the most mineralized and hardest tissue in it comprising up to 95 wt% of apatite; (b) its microstructure is dominated by parallel rods composed of bundles of 40 – 60 nm wide apatite crystals with aspect ratios reaching up to 1:10,000 and (c) not only does the protein matrix that gives rise to enamel guides the crystal growth, but it also conducts its own degradation and removal in parallel. Hence, when mimicking the process of amelogenesis in vitro, crystal growth has to …


Biomimetic Precipitation Of Uniaxially Grown Calcium Phosphate Crystals From Full-Length Human Amelogenin Sols, Vuk Uskoković, Wu Li, Stefan Habelitz Jan 2011

Biomimetic Precipitation Of Uniaxially Grown Calcium Phosphate Crystals From Full-Length Human Amelogenin Sols, Vuk Uskoković, Wu Li, Stefan Habelitz

Pharmacy Faculty Articles and Research

Human dental enamel forms over a period of 2 – 4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of a dense amelogenin matrix is presumed to direct the growth of apatite fibers and their organization into bundles that eventually comprise the mature enamel, the hardest tissue in the mammalian body. This work aims to establish the physicochemical and biochemical conditions for the synthesis of fibrous apatite crystals under the control of a recombinant fulllength human amelogenin matrix in combination with a programmable titration system. The growth …


Enzymatic Processing Of Amelogenin During Continuous Crystallization Of Apatite, Vuk Uskoković, M.-K. Kim, W. Li, S. Habelitz Jan 2008

Enzymatic Processing Of Amelogenin During Continuous Crystallization Of Apatite, Vuk Uskoković, M.-K. Kim, W. Li, S. Habelitz

Pharmacy Faculty Articles and Research

Dental enamel forms through a protein-controlled mineralization and enzymatic degradation with a nanoscale precision that new engineering technologies may be able to mimic. Recombinant fulllength human amelogenin (rH174) and a matrix-metalloprotease (MMP-20) were employed in a pHstat titration system that enabled a continuous supply of calcium and phosphate ions over several days, mimicking the initial stages of matrix processing and crystallization in enamel in-vitro. Effects on the self-assembly and crystal growth from a saturated aqueous solution containing 0.4 mg/ml rH174 and MMP-20 with the weight ratio of 1:1000 with respect to rH174 were investigated. A transition from nanospheres to fibrous …