Repression of endo-1,4-beta-glucanase formation in Penicillium janthinellum and product inhibition of its 1,4-beta-glucanases and cellobiases

Endo-1,4-beta-glucanase formation of Penicillium janthinellum was repressed by glucose, sophorose, and glycerol. Chromatography on DEAE-Sephadex A-50 was employed to separate the 1,4-beta-glucanases from two cellobiases. The 1,4-beta-glucanases were inhibited competitively by cellobiose and glucose, and the two cellobiases were inhibited by glucose and glucono-delta-lactone.     

Efficacy of mycobacterial components in the immunotherapy of mice with pulmonary tumor deposits

Summary The effectiveness of each of two mycobacterial components and a synthetic analog of one of them in the eradication of pulmonary deposits of intravenously injected syngeneic fibrosarcoma 1023 in C3H mice was studied. BCG cell walls (BCG CW), trehalose 6,6-dimycolate (TDM) or 6,6-di-0-2-tetradecyl, 3-hydroxyoctadecanoyl-,-trehalose (C76), a synthetic analog of TDM, was administered in emulsified form by three different routes: intraperitoneal, intradermal, or intravenous, 24 h after intravenous injection of 1023 tumor cells. The most effective form of therapy was TDM given by the intraperitoneal route; about 50% of treated animals were cured. Higher doses of BCG CW or C76 also led to a significant number of cures. Each agent caused a significant prolongation of survival time of the treated mice at two or more of the dosages tested; however, their routes of optimal activity varied.     

Normal mouse serum contains peptides which induce fibroblasts to grow in soft agar

The untransformed mouse fibroblast cells NIH/3T3, C3H/10T1/2, and rat NRK cells do not grow in soft agar in medium supplemented with 10% fetal calf serum. When fetal calf serum in the growth medium was supplemented with less than 1% of sera from mice or other vertebrates, however, these cells responded, forming large colonies. The morphology of soft agar colonies was a function of the treated cell type. In the presence of 10% serum from C57BL/6 mice, NRK cells grew to smooth-surfaced spherical colonies, while NIH/3T3 colonies showed individual round cells on their surface and C3H/10T1/2 cells grew as extended cells forming columns of end to end connected fibroblasts. Mus Musculus Castaneus-Epithelial (MMC- E) cells were not stimulated to grow in soft agar under these conditions. The major fibroblast colony-inducing factor (F-CIF) was partially purified from mouse serum by acid/ethanol-extraction, gel permeation chromatography, and reverse-phase high-pressure liquid chromatography. F-CIF is a polypeptide, which does not compete for binding to epidermal growth factor (EGF) receptors, but stimulates normal fibroblasts to form small colonies in semisolid medium and very large colonies in the presence of added EGF (2 ng/ml). In contrast to unfractionated mouse serum, purified F-CIF did not induce C3H/10T1/2 cells to grow in soft agar, suggesting that serum contains additional cell type-specific agar growth-stimulating activities.     

Construction of a plasmid containing the complete coding region of human elongation factor 2.

A plasmid pUChEF-2 containing the coding sequence as well as the complete 3'-untranslated region (3'UTR) of human EF-2 mRNA was constructed. The plasmid construct was assembled from a cDNA insert of pHGR81 (Rapp et al., (1988) Biol. Chem. Hoppe-Seyler 369, 247-250) comprising the C-terminal portion of the coding region and the 3'UTR, as well as a polymer chain reaction PCR fragment (Rapp et al., (1989) Biol. Chem. Hoppe-Seyler 370, 1071-1075) covering the missing part of the coding region from the amino-terminus.     

Transformation of MMC-E epithelial cells by acute 3611-MSV: inhibition of collagen synthesis and induction of novel polypeptides

Mouse embryo epithelial cells MMC-E were transformed by novel fibrosarcoma-inducing murine sarcoma virus 3611-MSV. The cells were analyzed for the production and deposition of pericellular glycoproteins by immunofluorescence and by radioactive metabolic and cell surface labeling techniques followed by analysis in polyacrylamide gels and fluorography. The pericellular fibronectin matrix was lost, but unlike in virus-transformed fibroblastic cells, the production of fibronectin was not affected. The major differences detected were decrease in collagen production and initiation of synthesis of two major glycoproteins with Mr 58,000 and 60,000. Cell surface carbohydrate labeling indicated that after 3611-MSV transformation the cells expressed Mr 100,000 and 68,000 polypeptides. The present and previous results show that viral transformation of epithelial cells induces different transformed phenotypes that are associated with distinct alterations in pericellular glycoproteins.     

Pyruvate dehydrogenase complex from germinating castor bean endosperm

Subcellular organelles from castor bean (Ricinus communis) endosperm were isolated on discontinuous sucrose gradients from germinating seeds which were 1 to 7 days postimbibition. Marker enzyme activities of the organelles were measured (fumarase, catalase, and triose phosphate isomerase) and the homogeneity of the organelle fractions was examined by electron microscopy. Pyruvate dehydrogenase complex activity was measured only in the mitochondrial fraction and attempts to activate or release the enzyme from the proplastid were not successful. A pathway is proposed for the most efficient use of endosperm carbon for de novo fatty acid biosynthesis that does not require the presence of the pyruvate dehydrogenase complex in the proplastid to provide acetyl-coenzymeA.