Purification and Some Properties of an α-Amylase Inhibitor (Paim) from Streptomyces corchorushii

Paim, a microbial animal amylase inhibitor, was purified from the culture filtrate of Streptomyces corchorushii by salting out with ammonium sulfate and column chromatography on DEAE-cellulose, TEAE-cellulose, SP-Sephadex C-50, and Octyl Sepharose CL-4B. Paim was separated into 2 fractions (Paim I and II), both homogeneous on disc electrophoresis. The molecular weight of Paim I was 4100 and that of II, 4400 by amino acid analysis. Paim I and II consisted of 39 and 42 amino acid residues, respectively, and contained no lysine, isolecucine, or phenylalanine. Paim contained no carbohydrate moiety, and was stable even after being treated at 100°C for lOmin in the pH range from 5 to 8.     

Lytic Enzymes for Gram-negative Bacteria Produced by Bacillus subtilis YT-25

The available energy, gross protein value, phosphorus availability and palatability of 16 samples of single cell protein were evaluated in 20 bioassays using total 2,136 depleted chicks.

Four protein samples were products from Aspergillus tamarii grown on waste water of a fish processing factory, three were from Aspergillus oryzae grown on either acetic acid medium or cooked soybean waste, three were from Candida sp. grown on citrus molasses extracted from peel wastes of citrus processing plants, four were from Candida utitis grown on wood molasses produced from various wood wastes, and two were from Pseudomonas sp. and Alteromonas thlasomethanolica grown on methanol.

Five of 16 samples had excellent nutritive value, comparable to single cell proteins available commercially in Europe. All samples were palatable to the chicks, and no sign of acute toxicity was observed.     

Acceptor specificity of ATP:nucleoside-5'-phosphate pyrophosphotransferase from Streptomyces adephospholyticus. Synthesis of the 3'-pyrophosphates of pyrimidine nucleotides, some oligoribonucleotides, 5'-diphosphonucleosidic coenzymes and mG-5'-ppp-5'-Am.

ATP: nucleoside-5'-phosphate pyrophosphotransferase [EC 2.7.6.4] of Streptomyces adephospholyticus synthesizes not only 3'-pyrophosphates of 5'-purine ribomononucleotides but also those of pyrimidine mononucleotides, some short oligonucleotides, a variety of 5'-diphosphonucleosidic coenzymes and mG-5'-ppp-5'-Am.     

Enzymatic synthesis of anticodon-deleted and replaced Bacillus subtilis tRNAThr and their amino acid acceptor activity

By some enzymatic and chemical procedures, one or two nucleotides in the anticodon region of Bacillus subtilis tRNAThr were deleted and a part of the anticodon sequence was replaced. The anticodon-deleted molecules retained amino acid acceptor activity although the activity was low. However, the anticodon-replaced molecule which has a lysine specific sequence (U-U-U) exhibited neither threonine acceptor activity nor lysine acceptor activity.     

p53 prevents progression of nevi to melanoma predominantly through cell cycle regulation

p53 is the central member of a critical tumor suppressor pathway in virtually all tumor types, where it is silenced mainly by missense mutations. In melanoma, p53 predominantly remains wild type, thus its role has been neglected. To study the effect of p53 on melanocyte function and melanomagenesis, we crossed the ‘high-p53’Mdm4^+/− mouse to the well-established TP-ras^0/+ murine melanoma progression model. After treatment with the carcinogen dimethylbenzanthracene (DMBA), TP-ras^0/+ mice on the Mdm4^+/− background developed fewer tumors with a delay in the age of onset of melanomas compared to TP-ras^0/+ mice. Furthermore, we observed a dramatic decrease in tumor growth, lack of metastasis with increased survival of TP-ras^0/+: Mdm4^+/− mice. Thus, p53 effectively prevented the conversion of small benign tumors to malignant and metastatic melanoma. p53 activation in cultured primary melanocyte and melanoma cell lines using Nutlin-3, a specific Mdm2 antagonist, supported these findings. Moreover, global gene expression and network analysis of Nutlin-3-treated primary human melanocytes indicated that cell cycle regulation through the p21^WAF1/CIP1 signaling network may be the key anti-melanomagenic activity of p53.