Polyelectrolyte complex formation mediated immobilization of chitosan-invertase neoglycoconjugate on pectin-coated chitin

Saccharomyces cerevisiae invertase, chemically modified with chitosan, was immobilized on pectin-coated chitin support via polyelectrolyte complex formation. The yield of immobilized enzyme protein was determined as 85% and the immobilized biocatalyst retained 97% of the initial chitosan-invertase activity. The optimum temperature for invertase was increased by 10 °C and its thermostability was enhanced by about 10 °C after immobilization. The immobilized enzyme was stable against incubation in high ionic strength solutions and was 4-fold more resistant to thermal treatment at 65 °C than the native counterpart. The biocatalyst prepared retained 96 and 95% of the original catalytic activity after ten cycles of reuse and 74 h of continuous operational regime in a packed bed reactor, respectively.     

Identification of new Golgi complex specific proteins by direct organelle proteomic analysis

The Golgi complex is in the crossroad of the endocytic and secretory pathways. Its function is to post-translationally modify and sort proteins and lipids, and regulate the membrane balance in the cell. To understand the structure-function relationship of the Golgi complex the Golgi proteome has to be identified first. We have used a direct organelle proteomic analysis to identify new Golgi complex proteins. Enriched stacked Golgi membrane fractions from rat livers were isolated, and the proteins from these membranes were subsequently digested into peptides. The peptides were fractionated by cation-exchange chromatography followed by protein identification by automated capillary-LC/ESI-MS/MS analysis and database searches. Two different search programs, ProID and MASCOT were used. This resulted in a total of 1125 protein identifications in two experiments. In addition to the known Golgi resident proteins, a significant number of unknown proteins were identified. Some of these were further characterized in silico using different programs to provide insight into their structure, intracellular localization and biological functions. The Golgi localization of two of these newly identified proteins was also confirmed by indirect immunofluorescence.     

T cell epitope definition by differential mass spectrometry: identification of a novel, immunogenic HLA-B8 ligand directly from renal cancer tissue

In this study, we describe a differential mass spectrometric technique for the immuno-proteomic analysis of the major histocompatibility complex (MHC) peptides of a renal cell carcinoma (RCC) biopsy compared with the healthy kidney tissue of the same patient after nephrectomy. Using a stable isotope labeling approach, we could directly compare and relatively quantify 43 MHC-peptide pairs, most of which were present in similar proportions on both normal kidney and tumor. Significantly, two dominant peptides of monoisotopic masses ([M+H](+)) 973.43 u and 967.59 u, respectively, were found exclusively in the tumor sample. One of these was identified as originating from heme oxygenase-1 (HO-1), a protein involved in induction of apoptosis resistance, immuno-suppression and neoangiogenesis and reported to be up-regulated in various cancer types. Moreover, the corresponding synthetic HO-1-derived peptide was shown to be immunogenic in vitro by generation of CD8+ T cell lines with peptide-specific cytolytic activity. Thus, this peptide is an example of a differentially identified T cell epitope that could be considered as a target for immunotherapy.     

Interaction between Mnk2 and CBCVHL ubiquitin ligase E3 complex

MAP kinase-interacting kinase-2 (Mnk2) is one of the downstream kinases activated by MAP kinases. It phosphorylates the eukaryotic initiation factor 4E (elF4E), although the role of elF4E phosphorylation and the role of Mnk2 in the process of protein translation are not well understood. Except for elF4E, other physiological substrates of Mnk2 are still unidentified. To look for these unidentified substrates and to reveal the physiological function of Mnk2, we performed a yeast two-hybrid screening with Mnk2 as the bait. The results demonstrated Mnk2 could interact with VHL (von Hip-pel-Lindau tumor suppressor), Rbx1 (ring-box 1) and Cul2 (Cullin2) proteins in yeast cells. Furthermore, we validated the interaction between Mnk2 and VHL proteins in mammalian cells by co-immunoprecipitation analysis. Because the three proteins VHL, Rbx1 and Cul2 are all components of the CBCVHL ubiquitin ligase E3 complex, it has been shown that Mnk2 can interact with CBCVHL complex, and is probably one of the new substrates of the CBCVHL complex. Furthermore, during the interaction of Mnk2 with von Hippel-Lindau (VHL) tumor suppressor- binding protein 1 (VBP1), it appears that Mnk2 also joins to modulate cell shape as VBP1 plays an important role in the process of the maturation of the cytoskeleton and in the process of morphogenesis.     

光系统II核心复合物的稳态荧光光谱(英文)

在 83K 和 160K 两个温度下,通过激发波长对荧光发射谱的影响研究了光系统II中核心复合物的荧光光谱特性。用不同波长的光激发,核心复合物的发射谱的最大发射峰值不变,用 480、489、495 和 507nm 的光分别激发核心复合物,其光谱最大峰值处的荧光强度随不同激发波长下β-胡萝卜素分子的吸收强度的增大而降低,在长波长区域光谱的变化依赖于首先被激发的色素分子。所以,激发波长的不同影响着核心复合物中能量传递的途径。通过高斯解析,分析出核心复合物中至少存在有 7组叶绿素a组分,它们是Chla660,Chla670,Chla680,Chla682,Chla684,Chla687和Chla690。     

Mycobacterium paraterrae sp. nov. recovered from a clinical specimen: novel chromogenic slow growing mycobacteria related to Mycobacterium terrae complex

A previously unidentified, slowly growing scotochromogenic Mycobacterium was isolated from a Korean patient with symptomatic pulmonary infection. Phenotypically, this strain was generally similar to Mycobacterium terrae complex strains, however it uniquely produced orange pigmentation. Unique mycolic acid profiles and phylogenetic analyses based on three alternative chronometer molecules, 16S rRNA gene, hsp65 and rpoB , confirmed the taxonomic status of this strain as a novel species. These results support that this strain represents a novel Mycobacterium species. The name Mycobacterium paraterrae sp. nov. is proposed. The type strain is 05-2522 (= DSM 45127 = KCTC 19556).     

Marine genetic swamping: hybrids replace an obligately estuarine fish

Populations of obligately estuarine taxa are potentially small and isolated and may lack genetic variation and display regional differentiation as a result of drift and inbreeding. Hybridization with a wide‐ranging marine congener should introduce genetic variation and reduce the effects of inbreeding depression and genetic drift. However, high levels of hybridization can cause demographic and genetic swamping. In southeastern Australia hybridization occurs between obligately estuarine Black bream (Acanthopagrus butcheri) and migratory marine Yellowfin bream (Acanthopagrus australis). Here, we surveyed genetic variation at eight microsatellite loci and the mitochondrial control region of juvenile fish from five coastal lagoons (including temporal replication in two lagoons) (total n = 970) to determine the frequency and persistence of hybridization, and its likely consequence for the estuarine restricted A. butcheri. Of 688 juvenile fish genotyped 95% were either A. australis (347) or hybrids (309); only 5% (32) were A. butcheri. Most hybrids were later generation hybrids or A. butcheri backcrosses, which are likely multi‐generational residents within lagoons. Far greater proportions of hybrid juveniles were found within two lagoons that are generally closed to the ocean (>90% hybrid fish within generally closed lagoons vs. 12–27% in permanently or intermittently open lagoons). In both lagoons, this was consistent across multiple cohorts of fish [79–97% hybrid fish (n = 282)]. Hybridization and introgression represent a major threat to the persistence of A. butcheri and have yet to be investigated for large numbers of estuarine taxa.     

复杂胫骨平台骨折18例治疗方法探讨

目的探讨复杂胫骨平台骨折的治疗方法和临床疗效。方法自2006年1月至2008年6月,笔者对复杂胫骨平台骨折进行了手术治疗并获随访的病例共18例,所有病例术前均予X线、CT、MRI检查,并按Schatzker分型：IV型IO例,V型12例,VI型6例。结果平均随访8个半月,均获骨性愈合,无螺钉松动、断裂。根据Merchant标准综合评分：优12例,良4例,可2例。优良率83.3%。结论在良好复位,有效稳固的支撑固定下早期功能锻炼,不仅有利于骨折愈合,还对关节功能的最大恢复起着重要作用。