scholarly journals Isolation and characterization of circumferential microfilament bundles from retinal pigmented epithelial cells.

1982 ◽  
Vol 95 (1) ◽  
pp. 310-315 ◽  
Author(s):  
K Owaribe ◽  
H Masuda

Chicken retinal pigmented epithelial cells have circumferential microfilament bundles (CMBs) at the zonula adherens region. We have isolated these CMBs in intact form and characterized them structurally and biochemically. Pigmented epithelia obtained from 11-d-old chick embryos were treated with glycerol and Triton. Then, the epithelia were homogenized by passing them through syringe needles. Many isolated CMBs were found in the homogenate by phase-contrast microscopy. They formed polygons, mostly pentagons and hexagons, or fragments of polygons. Polygons were filled with meshwork structures, i.e. they were polygonal plates. Upon exposure to Mg-ATP, isolated CMBs showed clear and large contraction. The contraction was inhibited by treatment with N-ethylmaleimide-modified myosin subfragment-1. After purification by centrifugation with the density gradient of Percoll, CMBs were analyzed by SDS PAGE. The electrophoretic pattern gave three major components of 200, 55, and 42 kdaltons and several minor components. Electron microscopy showed that the polygons were composed of thick bundles of actin-containing microfilaments, and the meshworks were composed primarily of intermediate filaments.

2020 ◽  
Vol 11 ◽  
Author(s):  
Sandra Quilodrán-Vega ◽  
Leonardo Albarracin ◽  
Flavia Mansilla ◽  
Lorena Arce ◽  
Binghui Zhou ◽  
...  

Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate beneficial LAB from llama milk that can be used as potential probiotics active against bacterial pathogens. LAB strains were isolated from llama milk samples. In vitro functional characterization of the strains was performed by evaluating the resistance against gastrointestinal conditions and inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatory properties of the strains were assessed. The functional studies were complemented with a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillus salivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared to that of other tested strains. The TUCO-L2 strain was resistant to pH and high bile salt concentrations and demonstrated antimicrobial activity against Gram-negative intestinal pathogens and adhesion to mucins and epithelial cells. L. salivarius TUCO-L2 modulated the innate immune response triggered by Toll-like receptor (TLR)-4 activation in intestinal epithelial cells. This effect involved differential regulation of the expression of inflammatory cytokines and chemokines mediated by the modulation of the negative regulators of the TLR signaling pathway. Moreover, the TUCO-L2 strain enhanced the resistance of mice to Salmonella infection. This is the first report on the isolation and characterization of a potential probiotic/immunobiotic strain from llama milk. The in vitro, in vivo, and in silico investigation performed in this study reveals several research directions that are needed to characterize the TUCO-L2 strain in detail to position this strain as a probiotic or immunobiotic that can be used against infections in humans or animals, including llama.


Biochemistry ◽  
1984 ◽  
Vol 23 (17) ◽  
pp. 3994-4002 ◽  
Author(s):  
William J. Perkins ◽  
James A. Wells ◽  
Ralph G. Yount

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Chao Wang ◽  
Tianli Wei ◽  
Yiman Huang ◽  
Qiong Guo ◽  
Zhiping Xie ◽  
...  

1980 ◽  
Vol 58 (7) ◽  
pp. 797-801 ◽  
Author(s):  
Maryanne Vahey ◽  
Stylianos P. Scordilis

Proteins exhibiting all of the basic structural and biochemical characteristics of actin and myosin have been isolated from the parenchymal cells of the fruit of the tomato, Lycopersicon esculentum. Crude cytoplasmic extracts of these cells contain filaments that can be decorated by rabbit skeletal muscle myosin subfragment-1 (S-1). Polymerized tomato actin activates the Mg2+–ATPase of both skeletal and tomato myosin at physiological ionic strength. Tomato actin comigrates with skeletal actin on sodium dodecyl sulfate polyacrylamide gels (SDS-PAGE) indicating an apparent molecular weight of 45 000. High ionic strength extracts of tomato contain a myosin whose ATPase activity in 0.5 M KCl is maximal in the presence of K+-ethylenediaminetetraacetic acid (K+-EDTA) and is inhibited by Mg2+. Tomato myosin interacts with skeletal F-actin to form an actomyosin complex that can be dissociated by ATP. At low ionic strength the Mg2+–ATPase of the myosin can be activated by actin.


2012 ◽  
Vol 77 (9) ◽  
pp. C914-C920 ◽  
Author(s):  
Liang Zheng ◽  
Kefeng Yu ◽  
Chunhong Yuan ◽  
Xichang Wang ◽  
Shunsheng Chen ◽  
...  

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