TyrB26位点改变的人类胰岛素类似物的化学合成与体外活性

摘要：为了研究人类胰岛素B链第26位的酪氨酸对胰岛素和受体之间的结合的影响,包括单独的氨基酸替换或化合物替换的不同的胰岛素类似物被合成,其中化合物替代的类似物的B链C末端都减少了4个氨基酸。在对它们与胰岛素受体的亲和力进行研究中,结果发现它们与胰岛素受体的亲和力没有丢失, HisB26类似物和N-MeHisB26类似物的结合能力与胰岛素相比改变不大,分别是胰岛素的72 %和107 %。N-MeGluB26类似物,AadB26类似物和Phe (4-carboxy) B26类似物的结合能力有很大的提高,分别是130 %, 234 %和160 %。     

Kinetic analysis of the transformation of phthalate esters in a series of stoichiometric reactions in anaerobic wastes

Phthalates such as dimethyl phthalate, dimethyl terephthalate (DMT), diethyl phthalate (DEP), di(2-ethylhexyl) phthalate and mono(2-ethylhexyl) phthalate (MEHP) are degraded to varying degrees under anaerobic conditions in waste treatment systems. Here we kinetically analyse the enzymatic hydrolyses involved and the subsequent stoichiometric reactions. The resulting model indicates that the degradation of the alcohols released and the transformation of the phthalic acid (PA) result in biphasic kinetics for the methane formation during transformation of DMT, DEP and MEHP. The ester hydrolysis and the PA transformation to methane appear to be the two rate-limiting steps. The PA-fermenting bacteria, which have biomass-specific growth rates between 0.04 and 0.085 day⁻¹, grow more slowly than the other bacteria involved. Anaerobic microorganisms that remove intermediate products during phthalic acid ester conversion appear to be important for the efficiency of the ultimate phthalate degradation and to be inhibited by elevated hydrogen partial pressures. The model was based on (and the simulations corresponded well with) data obtained from experimental waste treatment systems.     

A Crosstalk between the Biorhythms and Gatekeepers of Longevity: Dual Role of Glycogen Synthase Kinase-3

Biochemistry (Moscow) - This review discusses genetic and molecular pathways that link circadian timing with metabolism, resulting in the emergence of positive and negative regulatory feedback...     

Molecular identity,morphology and taxonomy of the Rhynchospio glutaea complex with a key to Rhynchospio species (Annelida,Spionidae)

Rhynchospio glutaea (Ehlers, 1897 Ehlers, E. 1897. Polychaeten. Ergebnisse der Hamburger Magalhaensischen Sammelreise 1892/93. L. Friederichsen & Co., Hamburg, Germany. [Google Scholar]), Rhynchospio arenincola Hartman, 1936 Hartman, O. 1936. New species of Spionidae (Annelida Polychaeta) from the coast of California. University of California Publications in Zoology 41, 45–52. [Google Scholar] and Rhynchospio arenincola asiatica Chlebovitsch, 1959 Chlebovitsch, V.V. 1959. Species of Polychaeta worms from the Kurile Islands, which are new or recorded for the first time in the USSR fauna. Zoologichesky Zhurnal 38, 167–181. [Google Scholar], originally described from Strait of Magellan, California, and South Kurile Islands respectively, appear similar to each other in adult morphology. These species and subspecies have been considered by some authors as subjective synonyms and are here referred to as members of the R. glutaea complex. Sequence data of four gene fragments (2465 bp in total) of the mitochondrial 16S rDNA, nuclear 18S and 28S rDNA, and Histone 3 have shown that R. glutaea complex individuals from the South West Atlantic (Argentina), North East Pacific (British Columbia and Oregon) and North West Pacific (South Korea) were genetically distant and not conspecific. These data also indicate that R. arenincola from North America and R. aff. asiatica from South Korea are more closely related to each other, and both are closer to R. glutaea from South America than to R. nhatrangi from Vietnam: nhatrangi (glutaea (arenincola-aff. asiatica)). Adults of the R. glutaea complex are hermaphrodites and the arrangement of gametes is suggested to be a crucial reproductive character for distinguishing these species. Based on this character, two species of the complex are apparent in the North West Pacific: R. asiatica Chlebovitsch, 1959 Chlebovitsch, V.V. 1959. Species of Polychaeta worms from the Kurile Islands, which are new or recorded for the first time in the USSR fauna. Zoologichesky Zhurnal 38, 167–181. [Google Scholar] stat. nov. from the Kurile Islands (not analysed here) and an unnamed species from the mainland coast of Asia (here referred to as R. aff. asiatica). Adult morphology of R. asiatica stat. nov. is briefly described and illustrated. The lectotype and the type locality of the species on Iturup Is. are established for the first time. An identification key is provided to the 10 currently recognized Rhynchospio species.     

How the Motility Pattern of Bacteria Affects Their Dispersal and Chemotaxis

Most bacteria at certain stages of their life cycle are able to move actively; they can swim in a liquid or crawl on various surfaces. A typical path of the moving cell often resembles the trajectory of a random walk. However, bacteria are capable of modifying their apparently random motion in response to changing environmental conditions. As a result, bacteria can migrate towards the source of nutrients or away from harmful chemicals. Surprisingly, many bacterial species that were studied have several distinct motility patterns, which can be theoretically modeled by a unifying random walk approach. We use this approach to quantify the process of cell dispersal in a homogeneous environment and show how the bacterial drift velocity towards the source of attracting chemicals is affected by the motility pattern of the bacteria. Our results open up the possibility of accessing additional information about the intrinsic response of the cells using macroscopic observations of bacteria moving in inhomogeneous environments.     

Occurrence of Fatty Acid Short‐Chain‐Alkyl Esters in Fruits of Celastraceae Plants

Small amounts of a mixture of fatty acid short‐chain‐alkyl esters (FASCAEs) were obtained from the fruits of twelve plant species of Celastraceae family, and in five of them the FASCAEs were present not only in the arils but also in the seeds. These mixtures contained 32 individual FASCAE species, which formed four separate fractions, viz. FA methyl, ethyl, isopropyl, and butyl esters (FAMEs, FAEEs, FAIPEs, and FABEs, resp.). The FASCAE acyl components included the residues of 16 individual C₁₄–C₂₄ saturated, mono‐, di‐, and trienoic FAs. Linoleic, oleic, and palmitic acids, and, in some cases, also α‐linolenic acid predominated in FAMEs and FAEEs, while myristic acid was predominant in FAIPEs. It can be suggested that, in the fruit arils of some plant species, FAMEs and FAEEs were formed at the expense of a same FA pool characteristic of a given species and were strongly different from FAIPEs and FABEs esters regarding the mechanism of their biosynthesis. However, as a whole, the qualitative and quantitative composition of various FASCAE fractions, as well as their FA composition, varied considerably depending on various factors. Therefore, separate FASCAE fractions seem to be synthesized from different FA pools other than those used for triacylglycerol formation.