We identified the biosynthetic gene cluster for lucilactaene, a cell cycle inhibitor from a filamentous fungus Fusarium sp. RK 97-94. The luc1 knockout strain accumulated demethylated analogs, indicating the involvement of Luc1 methyltransferase in lucilactaene biosynthesis. Lucilactaene showed potent antimalarial activity. Our data suggested that methylation and ether ring formation are essential for its potent antimalarial activity.
Human dipeptidyl peptidase IV (hDPPIV) inhibitors provide an effective strategy for the treatment of type 2 diabetes. Because certain peptides are known to act as hDPPIV inhibitors, a dataset of possible peptides with their inhibition intensities will facilitate the development of functional food for type 2 diabetes. In this study, we examined a total of 337 dipeptides with respect to their hDPPIV inhibitory effects. Amino acid residues at N-termini dominated their inhibition intensities. Particularly highly inhibitory dipeptides discovered included the following novel dipeptides: Thr-His, Asn-His, Val-Leu, Met-Leu, and Met-Met. Using our dataset, prime candidates contributing to the hDPPIV inhibitory effect of soy protein hydrolyzates were successfully identified. Possible dietary proteins potentially able to produce particularly highly hDPPIV inhibitory peptides are also discussed on the basis of the dataset.
The single-crystal structure of anagliptin, N-[2-({2-[(2S)-2-cyanopyrrolidin-1-yl]-2-oxoethyl}amino)-2-methylpropyl]-2-methyl pyrazolo[1,5-a]pyrimidine-6-carboxamide, was determined. Two independent molecules were held together by intermolecular hydrogen bonds, and the absolute configuration of the 2-cyanopyrrolidine ring delivered from l-prolinamide was confirmed to be S. The interactions of anagliptin with DPP-4 were clarified by the co-crystal structure solved at 2.85 A resolution. Based on the structure determined by X-ray crystallography, the potency and selectivity of anagliptin were discussed, and an SAR study using anagliptin derivatives was performed.
Title: Systematic analysis of a dipeptide library for inhibitor development using human dipeptidyl peptidase IV produced by a Saccharomyces cerevisiae expression system Hikida A, Ito K, Motoyama T, Kato R, Kawarasaki Y Ref: Biochemical & Biophysical Research Communications, 430:1217, 2013 : PubMed
The inhibition of human dipeptidyl peptidase IV/CD26 (hDPPIV) is an accepted treatment for type 2 diabetes. In this study, an extracellular production system of hDPPIV using Saccharomyces cerevisiae was established to facilitate the screening of hDPPIV inhibitors. As dipeptides that mimic the hDPPIV substrate are candidate inhibitors of this protein, X-Ala or X-Pro dipeptides (in which X represents any amino acid) were tested systematically. Based on the results obtained in the first screening, a second screening was performed for Trp-X dipeptides. To elucidate the manner via which the physicochemical features at the P(1) and P(2) positions contributed to the hDPPIV inhibitory effect, correlations between the inhibitory activity of dipeptides and 13 amino acid indices were analyzed. The most effective inhibitory dipeptide was Trp-Pro (K(i)=0.04 mM). The mode of inhibition of hDPPIV by dipeptides was explained well by some amino acid indices and by the structure of the substrate-binding site of hDPPIV. The information obtained from the systematic analysis of a dipeptide library provides important clues for the development of hDPPIV targeting drugs and functional foods for type 2 diabetes.
The aim of this study was to identify proteins with aberrant expression in clear cell renal cell carcinoma (ccRCC), and elucidate their clinical utilities. The protein expression profiles of primary ccRCC tumor tissues and neighboring non-tumor tissues were obtained from 9 patients by two-dimensional difference gel electrophoresis and mass spectrometry. Comparative analysis of 3771 protein spots led to the identification of 73 proteins that were expressed at aberrant levels in tumor tissues compared with non-tumor tissues. Among these 73 proteins, we further focused on N-myc downstream-regulated gene 1 protein (NDRG1). NDRG1 expression is regulated by members of myc family as well as by p53, HIF1A, and SGK1. The biological and clinical significance of NDRG1 is controversial for various malignancies and no detailed studies on NDRG1 have been reported in ccRCC until our study. For the 82 newly enrolled ccRCC patients, immunohistochemical analysis revealed a significant association between nuclear NDRG1 and favorable prognosis (p<0.05). Multivariate analysis demonstrated the role of NDRG1 as an independent factor of progression-free survival (p=0.01). Subsequent in vitro gene suppression assay demonstrated that NDRG1 silencing significantly enhanced cell proliferation and invasion of RCC cells. The cytotoxic effects of NDRG1 up-regulation induced by an iron chelator were also confirmed. These findings suggest that nuclear NDRG1 has tumor suppressive effects, and the NDRG1 expression may have clinical values in ccRCC. Nuclear NDRG1 may provide additional insights on molecular backgrounds of ccRCC progression, and contribute to the development of novel therapeutic strategy.
