Cell aggregation, role

Pessac, B., and Defendi, V., 1972, Cell aggregation Role of acid mucopolysaccharides. Science 175 898. 

Klement IA, Skinner PJ, Kaytor MD, Yi H, Hersch SM, Clark HB, Zoghbi HY, Orr HT. Ataxin-1 nuclear localization and aggregation role in polyglutamine-induced disease in SCA1 transgenic mice [see comments]. Cell 1998 95 41-53. 

Carbohydrate-carbohydrate interactions have been suggested as mediators of cell adhesion and aggregation. Studies of four different interactions— sponge cell aggregation, embryo and myelin compaction, and melanoma cell adhesion— have provided insights into the role of the saccharides in these events. The biological context of these associations as well as the results of experiments using biophysical and chemical model systems are described. 

Abstract Chemical structure, polymer microstructme, sequence distribution, and morphology of acid-bearing polymers are important factors in the design of polymer electrolyte membranes (PEMs) for fuel cells. The roles of ion aggregation and phase separation in vinylic- and aromatic-based polymers in proton conductivity and water transport are described. The formation, dimensions, and connectivity of ionic pathways are consistently found to play an important role in determining the physicochemical properties of PEMs. For polymers that possess low water content, phase separation and ionic channel formation significantly enhance the transport of water and protons. For membranes that contain a high... 

Babel W, Ackermann JU, Breuer U (2001) Physiology, regulation, and limits of the synthesis of poly(3HB). Adv Biochem Eng Biotechnol 71 125-157 Bahat-Samet E, Castro-Sowinski S, Okon Y (2004) Arabinose content of extracellular polysaccharide plays a role in cell aggregation of Azospirillum brasilense. FEMS Microbiol Lett 237 195-203... 

Yeast flocculation is a reversible and asexual process of cell aggregation, which plays an important role in sedimentation to the bottom of the fermentation vessel. Adhesins or flocculins, the ceU-wafl glycoproteins, are responsible for flocculation, together... 

The primary roles of the surface membrane (Table 1) include control of cell growth and intracellular communication by surface contact phenomena, as well as control of metabolite transport between the cell and its environment. A third possible role of the membrane in free-living (nonaggregated) cells would be that of movement. Codes of recognition must exist within the cell membrane for the orderly development of cells within multicellular organisms. Proteins and nucleic acids are well accepted as informational macromolecules, and the addition of carbohydrate moieties to them enhances the informational capacity of these macromolecules (Whaley et al., 1972), making the presence of carbohydrates on the cell surface an important factor in cell aggregation and adhesion. 

Inspired by the many hydrolytically-active metallo enzymes encountered in nature, extensive studies have been performed on so-called metallo micelles. These investigations usually focus on mixed micelles of a common surfactant together with a special chelating surfactant that exhibits a high affinity for transition-metal ions. These aggregates can have remarkable catalytic effects on the hydrolysis of activated carboxylic acid esters, phosphate esters and amides. In these reactions the exact role of the metal ion is not clear and may vary from one system to another. However, there are strong indications that the major function of the metal ion is the coordination of hydroxide anion in the Stem region of the micelle where it is in the proximity of the micelle-bound substrate. The first report of catalysis of a hydrolysis reaction by me tall omi cell es stems from 1978. In the years that... 

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