Effect of homo poly(L-amino acids) on fibrin assembly: role of charge and molecular weight

Biochemistry ◽  
1989 ◽  
Vol 28 (3) ◽  
pp. 1384-1388 ◽  
Author(s):  
Marcus E. Carr ◽  
Roy Cromartie ◽  
Don A. Gabriel
Keyword(s):  
Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1180
Author(s):  
Kayvan Khoramipour ◽  
Karim Chamari ◽  
Amirhosein Ahmadi Hekmatikar ◽  
Amirhosein Ziyaiyan ◽  
Shima Taherkhani ◽  
...  

Adiponectin (a protein consisting of 244 amino acids and characterized by a molecular weight of 28 kDa) is a cytokine that is secreted from adipose tissues (adipokine). Available evidence suggests that adiponectin is involved in a variety of physiological functions, molecular and cellular events, including lipid metabolism, energy regulation, immune response and inflammation, and insulin sensitivity. It has a protective effect on neurons and neural stem cells. Adiponectin levels have been reported to be negatively correlated with cancer, cardiovascular disease, and diabetes, and shown to be affected (i.e., significantly increased) by proper healthy nutrition. The present review comprehensively overviews the role of adiponectin in a range of diseases, showing that it can be used as a biomarker for diagnosing these disorders as well as a target for monitoring the effectiveness of preventive and treatment interventions.


1958 ◽  
Vol 35 (4) ◽  
pp. 871-891 ◽  
Author(s):  
J. A. RAMSAY

1. Contrary to expectation, it is found that metabolically useful substances pass into the urine and are reabsorbed in the rectum. 2. The kinetics of penetration have been investigated for six amino acids, three sugars and urea. 3. The evidence indicates that these substances enter the urine by passive diffusion. 4. The role of the Malpighian tubules in the insect's excretory system is discussed in the light of these findings. It is suggested that the tubule is primarily a means whereby all soluble substances of low molecular weight are removed from the haemolymph and that in this respect it has analogies with the glomerulus as well as with the tubule of the vertebrate nephron.


1975 ◽  
Vol 147 (1) ◽  
pp. 111-118 ◽  
Author(s):  
R Felix ◽  
H Fleisch

The properties of a highly purified inorganic pyrophosphatase (pyrophosphate phosphohydrolase; EC 3.6.1.1) from pig scapula cartilage were studied. The enzyme had a molecular weight of 66 000 and a pH optimum of 7-8. It was markedly activated by magnesium, but not, or only to a much smaller degree, by other metal ions. PP1 was the only substrate found and had a Km value of 11 muM. The enzyme was not inhibited by phosphate and other inhibitors of alkaline phosphatase such as CN- minus, amino acids and theophylline; it was slightly inhibited by tartrate, formaldehyde and ammonium molybdate and strongly inhibited by F- minus, Ca2+ and other metal ions. The properties of the enzyme in the presence of concentrations of PP1 present in plasma (3.5 muM) were similar to those found at higher (2 mM) concentrations of PP1. The diphosphonates ethane-1-hydroxy-1,1-diphosphonate and dichloromethylenediphosphonate inhibited the enzyme in the presence of low PP1 concentrations. The characteristics of this enzyme are therefore similar to pyrophosphatases from other sources, such as from yeast and erythrocytes, and do not support a specific role of this enzyme in the calcification process.


1987 ◽  
Vol 42 (4) ◽  
pp. 394-400 ◽  
Author(s):  
D. Palm ◽  
R. Goerl ◽  
G. Weidinger ◽  
R. Zeier ◽  
B. Fischer

Abstract The complete 796 residue amino acid sequence of maltodextrin phosphorylase was deduced from the E. coli malP nucleotide sequence. The calculated molecular weight of 90 500, including pyridoxal phosphate, is significantly larger than experimentally determined values. Enzymatically active and inactive mutants following deletion or exchange of up to 8 codons (7 amino acids) at the 3′ end (C-terminus) confirm the size of the mature native enzyme and disclose the essential functional or structural role of the highly conserved C-terminal region of phosphorylases.


1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.


1981 ◽  
Vol 31 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Mohamed A. Ashy ◽  
Abd El-Galil ◽  
M. Khalil ◽  
Abou-Zeid A. Abou-Zeid
Keyword(s):  

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.


2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.


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