Conjugated Amino Acids in the Non-Cationic Fraction of Pea Seedlings

Many amino acids were liberated by acid hydrolysis of the non-cationic fraction of pea seedling extract, suggesting the existence of ninhydrin-negative conjugated amino acids. The non-cationic fraction was subjected to cellulose column chromatography and gel-filtration with Sephadex G-15 and was separated into 20 fractions which gave ninhydrin color after alkaline hydrolysis. Alanine and glutamic acid, the most predominant amino acids in the hydrolyzate of the non-cationic fraction, occurred in many fractions. These results indicated that alanine and glutamic acid existed in various conjugated forms. In one of the fractions, there was evidence suggesting the presence of a peptide containing equimolar amounts of alanine and glutamic acid.     

Further Purification of Amylase Inhibitor Produced by Streptomyces sp.

The amylase inhibitor produced by Streptomyces sp. consisted of, at least, three kinds of inhibiting materials (inhibitor A, B and C). These inhibitors were separated by the Chromatographic techniques on Amberlite CG–120 and Dowex 1 × 2, and by paper chromatography etc.

Inhibitor A, B and C seemed to contain both carbohydrates and amino acids, but the specific activities (I. U./mg glucose) of the inhibitors A, B and C were different, that is, 18,800, 45,700 and 59,000, respectively. Also their ratios of amino acids to neutral sugars (expressed by moles of leucine per those of glucose) were approximately 0.09 (inhibitor A), 2.77 (inhibitor B) and 0.58 (inhibitor C).     

The role of autoimmune regulator (Aire) in the development of the immune system

AIRE is the gene responsible for a rather rare hereditary type of autoimmune disease. The mechanism underlying the autoimmune pathogenesis caused by AIRE deficiency is a focus of intense research because it could provide clues to the fundamental question of how the immune system discriminates between self and non-self within the thymic microenvironment.     

Biophysical Stability and Enzymatic Recognition of Oxanine in Dna

Oxanine (Oxa), which is one of the major products generated from guanine by nitrosative oxidation and is as long-lived as Gua in DNA, has been thought to be one of the major causes for NO-induced DNA damage. In the present study, using several synthetic Oxa-containing oligodeoxynucleotides, biophysical stability and enzymatic recognition of Oxa was investigated in DNA strands. It was found that Oxa did not mediate marked distortion in the whole DNA structure although Oxa pairing with 4 normal bases decreased thermal stability of the DNA duplexes compared to Gua:Cyt base pair. Regarding the responses of the DNA-relevant enzymes to Oxa, it was determined that Oxa was recognized as Gua except that DNA polymerases incorporated Thy as well as Cyt opposite Oxa. These results imply that Oxa tends to behave as a kind of naturally occurring base, Gua and therefore, would be involved in the genotoxic and cytotoxic threats of NO in cellular system.     

Erythropoietin Receptor Antagonist Suppressed Ectopic Hemoglobin Synthesis in Xenografts of HeLa Cells to Promote Their Destruction

The aim of this study is to explore a cause-oriented therapy for patients with uterine cervical cancer that expresses erythropoietin (Epo) and its receptor (EpoR). Epo, by binding to EpoR, stimulates the proliferation and differentiation of erythroid progenitor cells into hemoglobin-containing red blood cells. In this study, we report that the HeLa cells in the xenografts expressed ε, γ, and α globins as well as myoglobin (Mb) to produce tetrameric α2ε2 and α2γ2 and monomeric Mb, most of which were significantly suppressed with an EpoR antagonist EMP9. Western blotting revealed that the EMP9 treatment inhibited the AKT-pAKT, MAPKs-pMAPKs, and STAT5-pSTAT5 signaling pathways. Moreover, the treatment induced apoptosis and suppression of the growth and inhibited the survival through disruption of the harmonized hemoprotein syntheses in the tumor cells concomitant with destruction of vascular nets in the xenografts. Furthermore, macrophages and natural killer (NK) cells with intense HIF-1α expression recruited significantly more in the degenerating foci of the xenografts. These findings were associated with the enhanced expressions of nNOS in the tumor cells and iNOS in macrophages and NK cells in the tumor sites. The treated tumor cells exhibited a substantial number of perforations on the cell surface, which indicates that the tumors were damaged by both the nNOS-induced nitric oxide (NO) production in the tumor cells as well as the iNOS-induced NO production in the innate immune cells. Taken together, these data suggest that HeLa cells constitutively acquire ε, γ and Mb synthetic capacity for their survival. Therefore, EMP9 treatment might be a cause-oriented and effective therapy for patients with squamous cell carcinoma of the uterine cervix.