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441.
Rose M. McConnell Walter E. Godwin Amy Stefan Crystal Newton Nikki Myers Susan E. Hatfield 《Letters in Peptide Science》2003,10(2):69-78
Summary Cathepsin D, a lysosomal aspartic protease, has been suggested to play a role in the metastatic potential of several types
of cancer. A high activated cathepsin D level in breast tumor tissue has been associated with an increased incidence of relapse
and metastasis. High levels of active cathepsin D have also been found in colon cancer, prostate cancer, uterine cancer and
ovarian cancer. Hydroxyethyl isosteres with cyclic tertiary amine have proven to be clinically useful as inhibitors of aspartyl
proteases similar to cathepsin D in activity, such as the HIV-1 aspartyl protease. The design and the synthesis of (hydroxyethyl)amine
isostere inhibitors with cyclic tertiary amines is described. The IC50 and Ki(app) values for the six cathepsin D inhibitors and pepstatin are reported. Compounds7b,3(S)-[Acetyl-L-valyl-L-phenylalanylamino]-4-phenyl-1-N-piperidine-2(S)-butanol, and7c, 3(S)-[Acetyl-L-leucyl-L-phenylalanylamino]-4-phenyl-1-N-piperidine-2(S)-butanol, showed the most potent inhibition of cathepsin
D hydrolysis of hemoglobin with IC50 values of 3.5 nM and 4.5 nM, respectively. 相似文献
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The isolation of one amber mutation in malQ, one ochre mutation in malP, and seven amber mutations in malT is reported. A study of their phenotypic expressions in the presence of the amber suppressor su(III) and the ochre suppressor su(c) suggests that (i) malQ is the structural gene for amylomaltase; (ii) malQ and the structural gene for maltodextrin phosphorylase, malP, belong to the same operon; (iii) the malT product, which promotes the expression of the malP-malQ operon, is a protein synthesized in limiting amounts by the wild-type strain. 相似文献
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A new bipiperidyl-indole alkaloid, gramodendrine, was isolated from Lupinus arbustus subsp. calcaratus. Its structure was determined from spect 相似文献
449.
A mutant, PN6017, of the cellular slime mold Polysphondylium pallidum was selected by cell-surface labeling with a monoclonal antibody, mAb 293, and fluorescence-activated cell sorting. The antibody was directed against an L-fucose-containing epitope on glycoproteins, designated ep 293, and the mutant showed reduced and delayed expression of this epitope. PN6017 was distinguished from other mutants of this kind by extensive microcyst formation on agar plates under conditions where the wild type formed only sparse microcysts. In suspension cultures transformation of cells into microcysts was negligible in the wild type, and close to 100% in the mutant. Under these conditions microcyst formation in the mutant began at 5-7 h of starvation. At the same time expression of ep 293 and also of a developmentally regulated cytoplasmic protein, pallidin, became detectable. This coincidence in time suggests that microcyst formation in PN6017 is coupled to the same control mechanism as the two other developmentally regulated processes. 相似文献
450.
Dolph L. Hatfield Min-Hyuk Yoo Bradley A. Carlson Vadim N. Gladyshev 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009
Of the many health benefits attributed to selenium, the one that has received the most attention is its role in cancer prevention. Selenium-containing proteins (selenoproteins) have been shown in recent years to have roles in cancer prevention. However, selenoproteins have diverse functions and their view as antioxidants is oversimplified. Some selenoproteins appear to have a split personality in having roles both in preventing and promoting cancer. The contrasting roles of one selenoprotein, thioredoxin reductase 1, in cancer are discussed in detail, but as also noted, at least one other selenoprotein may also have such a dual function. In addition, we discuss examples of inhibition of cancer development by selenoprotein deficiency in mouse models. These studies highlight the complex nature of selenium in relation to cancer. 相似文献