The expression of a highly expressed Bacillus subtilis gene is not reduced by introduction of multiple codons normally not present in such genes

A recombinant DNA Proteus mirabilis L-form expression system, LVI (pJS127), was used to synthesize human fusion interferon alpha 1 (f-IFN-alpha 1). In the expression plasmid used, the complete coding sequence of IFN-alpha 1 was linked to the streptococcal speA promoter and the 5' end of the speA structural gene including its signal sequence coding region. LVI (pJS127) was capable of complete secretion into the culture medium of biologically active f-IFN-alpha 1 whose identity was confirmed by immunological and chemical evidence. In particular, bacterial L-forms were for the first time shown to be capable of correct signal peptide processing, as determined by N-terminal sequencing of the secreted f-IFN.     

茶皂素生产工艺及其应用的研究进展

本文综述了天然非离子表面活性剂茶皂素的生产工艺以及在实际中的应用 ,并就目前的生产和使用情况提出了一些看法和需要解决的问题。     

Guiding the Selection of Processing Additives for Increasing the Efficiency of Bulk Heterojunction Polymeric Solar Cells

In bulk heterojunction (BHJ) polymeric organic solar cells (OSCs), the use of processing additives in the material formulation has emerged as a promising, cost‐effective, and widely applicable method for optimizing the phase separation between the donor (D) and acceptor (A) materials, thus increasing their efficiency. So far, however, there has been no systematic approach for identifying suitable processing additives for a given D:A system. A method based on the Hansen solubility parameters (HSPs) is proposed for guiding the selection of processing additives for a given D:A combination. The method is applied to the archetypical poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM) system. The HSPs of these materials are determined and used to define a set of numerical criteria that need to be satisfied by a processing additive in order for it to be effective in realizing a higher efficiency OSC. Applying the selection criteria results in the identification of three novel processing additives. OSCs made of these formulations demonstrate an increase in their short‐circuit current density (J_SC) and power conversion efficiency (PCE). These results demonstrate the efficiency of these novel processing additives and show that the HSPs represent a useful tool to determine and explore new types of processing additives for BHJ‐OSCs.     

Anatomical brain asymmetry in monkeys: frontal, temporoparietal, and limbic cortex in Macaca

Measurements evaluating possible cerebral hemispheric asymmetries were taken by hand on frontal, parietal, and temporal cortex on 60 formalin-fixed Macaca mulatta and Macaca fascicularis brain specimens. No statistically significant (P less than 0.05) right/left side differences in the mean length of four sulci in visual-processing areas of the cortex were found. The sulcus adjacent to the region cytoarchitecturally homologous to the motor speech area in the human brain did not show pronounced asymmetry. In both species, however, a small parietal lobe sulcus showed greater development on the left hemisphere than in the right. In measurements made using digital planimetry, right/left side differences in the area of the dorsal cingulate gyrus were not found. Behavioral evidence suggests that monkeys do not exhibit a consistent pattern of cerebral dominance for functions associated with most of these regions of the brain.     

The loss in hydrophobic surface area resulting from a Leu to Val mutation at the N-terminus of the aldehyde dehydrogenase presequence prevents import of the protein into mitochondria

An apparent conservative mutation, Leu to Val, at the second residue of the rat liver mitochondrial aldehyde dehydrogenase (ALDH) presequence resulted in a precursor protein that was not imported into mitochondria. Additional mutants were made to substitute various amino acids with nonpolar side chains for Leu2. The Ile, Phe, and Trp mutants were imported to an extent similar to that of the native precursor, but the Ala mutant was imported only about one-fourth as well. It was shown that the N-terminal methionine was removed from the L2V mutant in a reaction catalyzed by methionine aminopeptidase. The N-terminal methionine of native pALDH and the other mutant presequences was blocked, presumably by acetylation. Because of the difference in co-translational modification, the L2V mutant sustained a significant loss in the available hydrophobic surface of the presequence. Import competence was restored to the L2V mutant when it was translated using a system that did not remove Met1. The removal of an Arg-Gly-Pro helix linker segment (residues 11-14) from the L2V mutant, which shifted three leucine residues toward the N-terminus, also restored import competence. These results lead to the conclusion that a minimum amount of hydrophobic surface area near the N-termini of mitochondrial presequences is an essential property to determine their ability to be imported. As a result, both electrostatic and hydrophobic components must be considered when trying to understand the interactions between precursor proteins and proteins of the mitochondrial import apparatus.     

Computational analysis of DNA photolyases using digital signal processing methods

Sun light energy is used by plants to trigger their growth and development. However, an increase of UV-B light may lead to DNA damage. DNA photolyases are enzymes that repair the cyclobutane pyridine dimer (CPD) and 6–4 photoproduct lesions formed through UV irradiation of DNA. Many aspects of the repair process are under intense scientific investigation but still poorly understood. Here we have computationally analysed DNA-photolyases using the resonant recognition model (RRM), a physico-mathematical approach based on digital signal processing methods. The RRM proposes that protein interactions represent the transfer of resonant electromagnetic energy between interacting molecules at the particular frequency. Within this study we have determined photolyases characteristic frequency, “hot spots” amino acids corresponding to the functional mutations and functional active/binding sites, and designed photolyase peptide analogous. A mutual relationship between photolyase and p53 tumour suppressor protein has also been investigated. The results obtained provide new insights into the structure–function relationships of photolyase protein family.     

荞麦粉营养品质与加工特性研究

通过对荞麦粉营养品质和加工特性的测定分析,结果表明：荞麦粉必需氨基酸含量高,氨基酸组成优于小麦面粉,接近WHO／FAO建议模式;荞麦粉的淀粉酶活性远低于小麦粉,是荞麦粉粘度远大于小麦粉以及降落值(Falling number)远高于小麦粉的主要原因之一。营养成分在荞麦子粒的不同部位的分布很不均衡,外层麸粉的营养价值高于内层心粉,但内层心粉的加工性能优于外层麸粉。     

Autoproteolytic Processing of Aspartic Proteinase from Sunflower Seeds

The autoproteolytic processing of mature aspartic proteinase from sunflower seeds was investigated. The mature aspartic proteinase (48 kDa) was processed at N65s-D66s in the plant-specific region of the enzyme to form 34-kDa and 14-kDa subunits. The next step was the hydrolysis of the A25s-Q26s and N97s-E98s bonds to form a 39-kDa enzyme that consisted of 29-kDa and 9-kDa disulfide-bonded subunits. Finally, bonds including V1s-M2s, M2s-S3s, C100s-D101s, and D101s-R102s were cleaved to form non-covalently bound subunits (29 kDa and 9 kDa) by eliminating the disulfide bonds in the plant-specific region of the protein.