A new low-molecular-weight calcium-binding ligand in rat small intestine

Life Sciences ◽  
1983 ◽  
Vol 33 (24) ◽  
pp. 2399-2408 ◽  
Author(s):  
M.K. Song ◽  
M.A. Song ◽  
D.B.N. Lee
Keyword(s):  
Molecular Weight ◽  
Small Intestine ◽  
Calcium Binding ◽  
Low Molecular Weight ◽  
Rat Small Intestine

Goblet Cell Mucin of Rat Small Intestine. Chemical and Physical Characterization

1973 ◽  
Vol 51 (8) ◽  
pp. 1154-1166 ◽  
Author(s):  
Janet F. Forstner ◽  
Inderjit Jabbal ◽  
Gordon G. Forstner
Keyword(s):  
Molecular Weight ◽  
Small Intestine ◽  
Goblet Cell ◽  
Disulfide Bonds ◽  
Axial Ratio ◽  
Dry Weight ◽  
Subunit Structure ◽  
Rat Small Intestine ◽  
Minor Components ◽  
Sulfur Containing

Goblet cell mucin (GCM) of rat small intestine has been isolated previously, and its location established by immunofluorescence techniques. In the present study, GCM was characterized more fully by chemical and physical methods. It was found to be a flexible negatively charged macromolecule with a molecular weight of about 2.0 × 106, an intrinsic viscosity of 15.3 dl/g, and an axial ratio of about 225:1. Its composition was protein 12%, total hexose 23%, hexosamine 22.4%, sialic acid 10%, fucose 6.6%, and sulfate < 1% of the dry weight. It contained approximately 34 disulfide bonds per molecule. Like most mucin glycoproteins it was rich in serine, threonine, and proline (45.5 mol %) and poor in hydrophobic and sulfur containing amino acids. One major and two minor components were identified by acrylamide disc gel electrophoresis and analytic ultracentrifugation. The components appeared to represent different molecular weight species of GCM. No evidence of subunit structure could be obtained using a variety of techniques, including the disruption of ionic, hydrophobic, and disulfide bonds by detergents, denaturants, or reducing agents.

scholarly journals Plasma Adiponectin Complexes Have Distinct Biochemical Characteristics

Endocrinology ◽  
2008 ◽  
Vol 149 (5) ◽  
pp. 2270-2282 ◽  
Author(s):  
Todd Schraw ◽  
Zhao V. Wang ◽  
Nils Halberg ◽  
Meredith Hawkins ◽  
Philipp E. Scherer
Keyword(s):  
Molecular Weight ◽  
Calcium Binding ◽  
Secretory Pathway ◽  
Fluorescent Label ◽  
Major Influence ◽  
Low Molecular Weight ◽  
Mutant Form ◽  
Filtration Method ◽  
Molecular Weight Form

Adipocytes release the secretory protein adiponectin in a number of different higher-order complexes. Once synthesized and assembled in the secretory pathway of the adipocyte, these complexes circulate as biochemically distinct and stable entities with little evidence of interchange between the different forms that include a high-molecular-weight (HMW) species, a hexamer (low-molecular-weight form), and a trimeric form of the complexes. Here, we validate a high-resolution gel filtration method that reproducibly separates the three complexes in recombinant adiponectin and adiponectin from human and murine samples. We demonstrate that the HMW form is prominently reduced in male vs. female subjects and in obese, insulin-resistant vs. lean, insulin-sensitive individuals. A direct comparison of human and mouse adiponectin demonstrates that the trimer is generally more abundant in human serum. Furthermore, when the production of adiponectin is reduced, either by obesity or in mice carrying only a single functional allele of the adiponectin locus, then the amount of the HMW form is selectively reduced in circulation. The complex distribution of adiponectin can be regulated in several ways. Both mouse and human HMW adiponectin are very stable under basic conditions but are exquisitely labile under acidic conditions below pH 7. Murine and human adiponectin HMW forms also display differential susceptibility to the presence of calcium in the buffer. A mutant form of adiponectin unable to bind calcium is less susceptible to changes in calcium concentrations. However, the lack of calcium binding results in a destabilization of the structure. Disulfide bond formation (at position C39) is also important for complex formation. A mutant form of adiponectin lacking C39 prominently forms HMW and trimer but not the low-molecular-weight form. Injection of adiponectin with a fluorescent label reveals that over time, the various complexes do not interconvert in vivo. The stability of adiponectin complexes highlights that the production and secretion of these forms from fat cells has a major influence on the circulating levels of each complex.

scholarly journals Polyethylene glycol as marker in piglet diets with a high dry-matter content

1968 ◽  
Vol 22 (3) ◽  
pp. 515-526 ◽  
Author(s):  
M. J. Manners ◽  
D. E. Kidder
Keyword(s):  
Molecular Weight ◽  
Small Intestine ◽  
Polyethylene Glycol ◽  
Dry Matter ◽  
Matter Content ◽  
Low Molecular Weight ◽  
Dry Matter Content ◽  
Casein Diet ◽  
High Dry Matter ◽  
Weight Substance

1. Polyethylene glycol (PEG) of high molecular weight, used as a dietary marker, did not distribute uniformly in the water present in a high-casein diet as did glucose, a low-molecular-weight substance.2. This distribution effect also occurred with the contents of the stomach and, to a smaller extent, with the contents of the first quarter of the small intestine of piglets given such a diet.

scholarly journals Calcium binding and calcium-induced gelation of normal low-methoxyl pectin modified by low molecular-weight polyuronate fraction

2017 ◽  
Vol 69 ◽  
pp. 318-328 ◽  
Author(s):  
Makoto Nakauma ◽  
Takahiro Funami ◽  
Yapeng Fang ◽  
Katsuyoshi Nishinari ◽  
Kurt I. Draget ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Calcium Binding ◽  
Low Molecular Weight

Occurrence of heparin and multisulfated chondroitins in the rat gastrointestinal tract and effect of fat feeding

1980 ◽  
Vol 58 (4) ◽  
pp. 416-423 ◽  
Author(s):  
Louis B. Jaques ◽  
Sandra Wice
Keyword(s):  
Molecular Weight ◽  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Electrolyte Concentration ◽  
Glucose Solution ◽  
Rat Small Intestine ◽  
Bacterial Enzymes ◽  
Micro Scale ◽  
Glucose Feeding ◽  
Fat Feeding

Rats were fed glucose solution for 3 days and killed without fasting. Examination of the crude polysaccharides extracted from the gastrointestinal tract by electrophoresis on the micro scale and using critical electrolyte concentration and bacterial enzymes showed three types of sulfated mucopolysaccharides were present. These were identified as heparitins, multisulfated chondroitins, and heparins. The heparin resembled a macromolecular heparin of moderate molecular weight. Following oil feeding, only the heparitins and muitisulfated chondroitins were present in the small intestine, and no heparin was found. With fasting for 12 h after glucose feeding, the amount of the heparin fraction in the small intestine was reduced. The results obtained demonstrate the presence of a heparin in the rat small intestine which is responsive to changes in diet.

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