scholarly journals Achievement of high rates of in vitro synthesis of 1,4-beta-D-glucan: activation by cooperative interaction of the Acetobacter xylinum enzyme system with GTP, polyethylene glycol, and a protein factor.

1982 ◽  
Vol 79 (21) ◽  
pp. 6448-6452 ◽  
Author(s):  
Y. Aloni ◽  
D. P. Delmer ◽  
M. Benziman
Blood ◽  
1950 ◽  
Vol 5 (7) ◽  
pp. 648-659 ◽  
Author(s):  
A. NIZET ◽  
F. S. ROBSCHEIT-ROBBINS

Abstract Ripening time of reticulocytes has been measured in dogs with an experimental hemorrhagic anemia and in "doubly depleted" dogs (anemia plus hypoproteinemia). In dogs submitted to hemorrhagic anemia alone, receiving a basal protein containing diet low in iron, the ripening time is the same as in nonanemic dogs, regardless of the potency for hemoglobin synthesis of any supplementary diet. In anemic and hypoproteinemic dogs, i.e., "doubly depleted" dogs, a close relationship exists between the rate of hemoglobin regeneration and the ripening time of reticulocytes. Feeding a basal nonprotein diet results in a block of the ripening effect; however, if a potent diet for hemoglobin regeneration is given, the ripening time becomes normal. Measurement of the ripening time in a "doubly depleted" dog provides a gross evaluation of the potency of a diet, as it concerns hemoglobin synthesis. The block of reticulocyte ripening in doubly depleted dogs may be lifted by addition of amino acids to the blood in vitro. Only the ten amino acids essential for growth and glycine are necessary. It appears therefore that the block in double depletion is caused essentially by the depletion of some protein factor or factors. The significance of these experimental results is discussed, relative to the problem of in vivo and in vitro synthesis of hemoglobin.


1987 ◽  
Vol 114 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Chohei Shigeno ◽  
Itsuo Yamamoto ◽  
Shegiharu Dokoh ◽  
Megumu Hino ◽  
Jun Aoki ◽  
...  

Abstract. We have partially purified a tumour factor capable of stimulating both bone resorption in vitro and cAMP accumulation in osteoblastic ROS 17/2 cells from three human tumours associated with humoral hypercalcaemia of malignancy. Purification of tumour factor by sequential acid urea extraction, gel filtration and cation-exchange chromatography, reverse-phase high performance liquid chromatography followed by analytical isoelectric focussing provided a basic protein (pI > 9.3) with a molecular weight of approximately 13 000 as a major component of the final preparation which retained both the two bioactivities. Bone resorbing activity and cAMP-increasing activity in purified factor correlated with each other. cAMP-increasing activity of the factor was heat- and acid-stable, but sensitive to alkaline ambient pH. Treatment with trypsin destroyed cAMP-increasing activity of the factor. Synthetic parathyroid hormone (PTH) antagonist, human PTH-(3– 34) completely inhibited the cAMP-increasing activity of the factor. The results suggest that this protein factor, having its effects on both osteoclastic and osteoblastic functions, may be involved in development of enhanced bone resorption in some patients with humoral hypercalcaemia of malignancy.


Author(s):  
Parth Sarthi Sen Gupta ◽  
Satyaranjan Biswal ◽  
Saroj Kumar Panda ◽  
Abhik Kumar Ray ◽  
Malay Kumar Rana

<p>While an FDA approved drug Ivermectin was reported to dramatically reduce the cell line of SARS-CoV-2 by ~5000 folds within 48 hours, the precise mechanism of action and the COVID-19 molecular target involved in interaction with this in-vitro effective drug are unknown yet. Among 12 different COVID-19 targets studied here, the RNA dependent RNA polymerase (RdRp) with RNA and Helicase NCB site show the strongest affinity to Ivermectin amounting -10.4 kcal/mol and -9.6 kcal/mol, respectively. Molecular dynamics of corresponding protein-drug complexes reveals that the drug bound state of RdRp with RNA has better structural stability than the Helicase NCB site, with MM/PBSA free energy of -135.2 kJ/mol, almost twice that of Helicase (-76.6 kJ/mol). The selectivity of Ivermectin to RdRp is triggered by a cooperative interaction of RNA-RdRp by ternary complex formation. Identification of the target and its interaction profile with Ivermectin can lead to more powerful drug designs for COVID-19 and experimental exploration. </p>


2005 ◽  
Vol 32 (4) ◽  
pp. 294-299 ◽  
Author(s):  
Dieter Hoffmann ◽  
Bernd Buchberger ◽  
Cordula Nemetz

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