Amelogenin, the major protein of tooth enamel: A new phylogenetic marker for ordinal mammal relationships

Amelogenin, the major protein component of tooth enamel, is shown to be a cell adhesion protein. Since it had been shown that an amelogenin-containing preparation, Emdogain®, possessed cell-adhesive activity, we tested the hypothesis that amelogenin was responsible for cell-adhesive activity. Recombinant amelogenin was found to promote adhesion at less than 15 μg/60-mm plate and requires divalent cations for activity. While we found that amelogenin does not bind to collagen or heparin under physiological conditions, it was demonstrated previously that amelogenin does bind to hydroxyapatite. The cell-adhesive activity of amelogenin may play a role in development and may provide a partial explanation for the therapeutic effects of Emdogain® in periodontal regeneration.

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The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065870 ◽

1971 ◽

Vol 29 ◽

pp. 366-367

Author(s):

M. Kessel ◽

R. MacColl

Keyword(s):

Self Assembly ◽

Analytical Ultracentrifugation ◽

Uranyl Acetate ◽

The Self ◽

Major Protein ◽

Subunit Structure ◽

Blue Green Alga ◽

Thin Sections ◽

Blue Green Algae ◽

Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

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Reading the phosphorylation code: binding of the 14-3-3 protein to multivalent client phosphoproteins

Biochemical Journal ◽

10.1042/bcj20200084 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1219-1225 ◽

Cited By ~ 4

Author(s):

Nikolai N. Sluchanko

Keyword(s):

Protein Function ◽

Intrinsically Disordered Protein ◽

Structural Basis ◽

Major Protein ◽

Post Translational Modifications ◽

Protein Protein Interaction ◽

Intrinsically Disordered ◽

Biochemical Journal ◽

Multiple Binding ◽

And Control

Many major protein–protein interaction networks are maintained by ‘hub’ proteins with multiple binding partners, where interactions are often facilitated by intrinsically disordered protein regions that undergo post-translational modifications, such as phosphorylation. Phosphorylation can directly affect protein function and control recognition by proteins that ‘read’ the phosphorylation code, re-wiring the interactome. The eukaryotic 14-3-3 proteins recognizing multiple phosphoproteins nicely exemplify these concepts. Although recent studies established the biochemical and structural basis for the interaction of the 14-3-3 dimers with several phosphorylated clients, understanding their assembly with partners phosphorylated at multiple sites represents a challenge. Suboptimal sequence context around the phosphorylated residue may reduce binding affinity, resulting in quantitative differences for distinct phosphorylation sites, making hierarchy and priority in their binding rather uncertain. Recently, Stevers et al. [Biochemical Journal (2017) 474: 1273–1287] undertook a remarkable attempt to untangle the mechanism of 14-3-3 dimer binding to leucine-rich repeat kinase 2 (LRRK2) that contains multiple candidate 14-3-3-binding sites and is mutated in Parkinson's disease. By using the protein-peptide binding approach, the authors systematically analyzed affinities for a set of LRRK2 phosphopeptides, alone or in combination, to a 14-3-3 protein and determined crystal structures for 14-3-3 complexes with selected phosphopeptides. This study addresses a long-standing question in the 14-3-3 biology, unearthing a range of important details that are relevant for understanding binding mechanisms of other polyvalent proteins.

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Tooth Enamel: Frontiers in Mineral Chemistry and Biochemistry, Integrative Cell Biology and Genetics

10.3389/978-2-88945-734-2 ◽

2019 ◽

Keyword(s):

Cell Biology ◽

Tooth Enamel ◽

Mineral Chemistry

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The role of the oral cavity immune cells in the postoperative complications after face lifting

ZHurnal «Patologicheskaia fiziologiia i eksperimental`naia terapiia» ◽

10.25557/0031-2991.2018.04.174-178 ◽

2018 ◽

pp. 174-178

Author(s):

Ш.М. Абрамян ◽

Е.В. Рожнова ◽

Е.Н. Волкова ◽

С.Н. Блохин ◽

С.Г. Морозов

Keyword(s):

Oral Cavity ◽

Immune Cells ◽

Postoperative Period ◽

Negative Impact ◽

Tooth Enamel ◽

Healing Time ◽

Negative Contribution ◽

Dental Diseases ◽

Induced Apoptosis ◽

Wound Healing Time

Цель. Изучение клеток иммунной системы полости рта у пациентов до проведения операции лифтинга лица, а также сопоставление этих данных с показателями, выявленными при осложнениях в послеоперационном периоде. Методика. Исследованы клетки иммунной системы полости рта 100 женщин (23-68 лет), которым перед операцией лифтинга лица проведено стоматологическое обследование и необходимое лечение при наличии кариеса дентина, клиновидного дефекта эмали зуба, хронического периодонтита или пульпита. Выделенные путем смывов десенной борозды клетки окрашивали моноклональными антителами и анализировали на проточном цитометре. Определяли уровень спонтанного и индуцированного апоптоза. Оценивали уровень фагоцитоза и генерацию супероксидного аниона нейтрофилами. Результаты. Показано, что хронические воспалительные заболевания зубов оказывают негативное влияние на состояние иммунных клеток ротовой полости, сопровождаются повышением генерации супероксидного аниона нейтрофилами, повышением уровня спонтанного и церамид-индуцированного апоптоза клеток десенной борозды. Заключение. Наличие хронической патологии зубов, даже после санации, оказывает негативное влияние на течение послеоперационного периода при проведении операции лифтинга лица, в частности, способствует увеличению времени заживления операционной раны, инфицированию раны с появлением очагов некроза в области операционного шва. The object. The study of the cells of the immune system of the oral cavity in patients before the operation of face lifting, as well as a comparison of these indicators with complications in the postoperative period. Methods. The immune cells from the oral cavity were studied in 100 women (23-68 years), who underwent a dental examination and necessary treatment if they had the dentin caries, wedge-shaped defect of tooth enamel, chronic periodontitis or pulpitis before the facial lifting operation. The immune cells have been isolated by a lavage of gingival sulcus around the damaged tooth. Results. It has been shown that chronic dental diseases made a negative contribution to the oral cavity immune cells. It has been accompanied by the elevated levels of superoxide originating from neutrophils as well as the increased levels of spontaneous and ceramide-induced apoptosis of immune cells isolated from the gingival sulcus. Conclusion. The presence of chronic pathology of teeth even in the case of the preoperative dental sanation has a negative impact on the postoperative period after face lifting, in particular, contributes to the lengthening of the surgical wound healing time, wound infection as well as the partial necrosis of suture.

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