Production of 19-hydroxy-11-deoxycorticosterone and 19-oxo-11-deoxycorticosterone from 11-deoxycorticosterone by cytochrome P-450(11)beta

Incubation of 11-deoxycorticosterone with a cytochrome P-450(11)beta-reconstituted system yielded, in addition to corticosterone and 18-hydroxy-11-deoxycorticosterone, a new steroid product. The retention time of the new product was identical with that of authentic 19-hydroxy-11-deoxycorticosterone on high performance liquid chromatography (HPLC). The turnover number of 19-hydroxy-11-deoxycorticosterone formation was 7.0 mol/min/mol P-450. When a large amount of cytochrome P-450(11)beta was used for the reaction and the products were analyzed by HPLC, the 19-hydroxy-11-deoxycorticosterone peak disappeared from the chromatogram and concomitantly new unidentified peaks appeared. These results suggest that 19-hydroxy-11-deoxycorticosterone was further metabolized to other steroids by cytochrome P-450(11)beta. Therefore, we next incubated 19-hydroxy-11-deoxycorticosterone with cytochrome P-450(11)beta and analyzed the reaction products by HPLC. The above-mentioned unidentified peaks appeared again in the chromatogram. The retention time of one of the peaks coincided with that of authentic 19-oxo-11-deoxycorticosterone. This peak substance was purified by repeated HPLC and subjected to mass spectrometry and 1H NMR analyses. Its field desorption mass spectrum (FD-MS) showed a M+ peak at m/e 344. The 1H NMR spectrum showed the signal of an aldehyde proton instead of those of hydroxymethyl protons at the C-19 position. These results suggest that cytochrome P-450(11)beta can catalyze the 19-hydroxylation of 11-deoxycorticosterone, and the 19-hydroxy-11-deoxycorticosterone produced is further oxidized at the C-19 position to 19-oxo-11-deoxycorticosterone.     

Elucidation of structural and antigenic properties of pneumococcal serotype 11A, 11B, 11C, and 11F polysaccharide capsules

Despite the emerging impact of serogroup 11 serotypes in Streptococcus pneumoniae epidemiology, the structures of serogroup 11 capsule types have not been fully elucidated, particularly the locations of O-acetyl substitutions. Here, we report the complete structures of the serotype 11B, 11C, and 11F polysaccharides and a revision to the serotype 11A capsular polysaccharide using nuclear magnetic resonance (NMR). All structures shared a linear, tetrasaccharide backbone with a pendant phosphopolyalcohol. Three of four saccharides are conserved in all serotypes. The individual serotype capsules differed in the identity of one saccharide, the pendant phosphopolyalcohol, and the O-acetylation pattern. Though the assigned locations of O-acetate substitutions in this study differed from those of previous reports, our findings were corroborated with strong correlations to serology and genetics. We examined the binding of serotyping sera to serogroup 11 polysaccharides by using flow cytometry and an inhibition-type enzyme-linked immunosorbent assay (ELISA) and found that de-O-acetylation of capsular polysaccharides by mild hydrolysis decreases its immunoreactivity, supporting the crucial role of O-acetylation in the antigenicity of these polysaccharides. Due to strong correlations between polysaccharide structures and capsule biosynthesis genes, we were able to assign target substrates for the O-acetyltransferases encoded by wcwC, wcwR, wcwT, and wcjE. We identified antigenic determinants for serogroup 11 serotyping sera and highlight the idea that conventional serotyping methods are not capable of recognizing all putative variants of S. pneumoniae serogroup 11.     

Production of 19-oic-11-deoxycorticosterone from 19-oxo-11-deoxycorticosterone by cytochrome P-450(11)beta and nonenzymatic production of 19-nor-11-deoxycorticosterone from 19-oic-11-deoxycorticosterone

19-Oxo-11-deoxycorticosterone was incubated with a cytochrome P-450(11)beta-reconstituted system, and the metabolites were analyzed by high performance liquid chromatography(HPLC). The main product found after chromatography was collected and treated with diazomethane. HPLC and 1H-NMR analysis of the methylated derivative indicated that it was 19-oic-11-deoxycorticosterone methyl ester. When 19-oic-11-deoxycorticosterone was stored at -20 degrees C for 1 month, it was spontaneously converted to other steroids. Structural analysis of the main degradation product indicated that it was 19-nor-11-deoxycorticosterone. These results suggest that the conversion of 19-oxo-11-deoxycorticosterone to 19-oic-11-deoxycorticosterone occurs through the P-450(11)beta-catalyzed reaction, and that the 19-oic-11-deoxycorticosterone thus formed is nonenzymatically converted into 19-nor-11-deoxycorticosterone.     

Evolution of 11β-hydroxysteroid dehydrogenase-type 1 and 11β-hydroxysteroid dehydrogenase-type 3

A key regulator of glucocorticoid action is 11β-hydroxysteroid dehydrogenase-type 1 (11β-HSD1), which catalyzes the conversion of cortisone to cortisol, the biologically active glucocorticoid. 11β-HSD1 is a paralog of 11β-HSD3, whose physiological function remains unclear. As reported here, 11β-HSD3 has orthologs in sea urchin, amphioxus and Ciona, while 11β-HSD1 first appears in sharks. Thus, 11β-HSD3 arose before the evolution of glucocorticoid signaling, suggesting different ancestral function(s) for 11β-HSD3. Four perplexing findings arise from this evolutionary analysis: (1) 11β-HSD1 is not present in a ray-finned fish genome, (2) zebrafish and fathead minnow contain two isoforms of 11β-HSD3; (3) neither rat nor mouse contain 11β-HSD3 and (4) amphioxus contains 16 11β-HSD3 paralogs.     

人白细胞介素11融合蛋白切割位点的改变及成熟蛋白的纯化

将 h IL- 1 1 c DNA克隆入硫氧还蛋白基因融合表达载体 p TRXFUS的 trx A基因 3′末端 ,构建符合读码框的融合基因 ,并在两基因间改变原有的肠激酶切割位点 ,引入蛋白质的羟胺切割位点序列 ,该融合蛋白在大肠杆菌中表达量达 2 0 %以上 .经羟胺切割 ,柱层析等纯化步骤后 ,得到纯度98%以上的成熟 h IL - 1 1 .用 IL- 6依赖细胞株 7TDI及 MTT法测定生物学活性 ,比活达 8× 1 0 6 IU/mg.并对纯品进行了 Western blot,N端 1 5个氨基酸测序及 h IL- 1 1氨基酸组成等分析和鉴定     

Rab11-FIP4 interacts with Rab11 in a GTP-dependent manner and its overexpression condenses the Rab11 positive compartment in HeLa cells

We have recently identified Rab11-FIP4 as the sixth member of the Rab11-FIP family of Rab11 interacting proteins. Here, we demonstrate that Rab11-FIP4 interacts with Rab11 in a GTP-dependent manner and that its C-terminal region allows the protein to self-interact and interact with pp75/Rip11, Rab11-FIP2, and Rab11-FIP3. However, Rab11-FIP4 does not appear to interact directly with Rab coupling protein (RCP). We investigated the subcellular localisation of Rab11-FIP4 in HeLa cells and show that it colocalises extensively with transferrin and with Rab11. Furthermore, when overexpressed, it causes a condensation of the Rab11 compartment in the perinuclear region. We demonstrate that the carboxy-terminal region of Rab11-FIP4 (Rab11-FIP4(C-ter)) is necessary and sufficient for its endosomal membrane association. Expression of Rab11-FIP4(C-ter) causes a dispersal of the Rab11 compartment towards the cell periphery and does not inhibit transferrin recycling in HeLa cells. It is likely that Rab11-FIP4 serves as a Rab11 effector in a Rab11 mediated function other than transferrin recycling.     

Hydrolytic behavior of 5alpha-hydroxy-11beta- and 5beta-hydroxy-11alpha-substituted 19-norsteroids

Teutsch G. and Bélanger A. treated 5alpha,10alpha epoxides with Grignard-reagents catalyzed by copper(I) ions. The reaction with steroidal epoxides proceeded with complete regio- and stereospecificity, leading exclusively to the 11beta-substituted compounds. According to our synthetic strategy, the 5,10 epoxide isomers were not separated; instead, the pure 11beta, and in some cases, 11alpha-substituted molecules were isolated after the conjugate addition of the Grignard-reagents, followed by deketalization and dehydration. Surprisingly, appearance of a third compound was generally observed beside the expected deprotected products, and this compound turned out to have a 3-keto-5(10),9(11) structural unit. Starting from pure 3-ethylenedioxy-5alpha,10alpha-epoxy-estr-9(11)-ene-17-one and 3-ethylenedioxy-5beta,10beta-epoxy-estr-9(11)-ene-17-one, four model compounds were synthesized (11alpha- and 11beta-[4-[1,1-(ethylenedioxy)-ethyl]phenyl]-estra-, as well as 11alpha- and 11beta-cyclohexyl-estra-derivatives) to study the process of deprotection and dehydration. 3-keto-5(10),9(11)-derivatives were found to form after deketalization and dehydration only from 11alpha-substituted derivatives, while 11beta-derivatives resulted in only the expected 3-keto-5,9-diene structure. After observing this remarkable difference between the behavior of 11alpha-, 11beta-substituted isomers we decided to take a closer look at the processes of deketalization and dehydration. In order to carry out the hydrolysis under mild conditions, pyridinium paratoluenesulfonate, a weakly acidic salt, was applied. All the intermediate products observed by TLC were isolated. The outcome of the deprotection and elimination reactions can be rationalized by two factors: conjugation of olefins (with the 3-oxo-group or the 11-phenyl group) and orientation of groups to be eliminated.     

Clustered 11q23 and 22q11 breakpoints and 3:1 meiotic malsegregation in multiple unrelated t(11;22) families

The t(11;22) is the only known recurrent, non-Robertsonian constitutional translocation. We have analyzed t(11;22) balanced-translocation carriers from multiple unrelated families by FISH, to localize the t(11;22) breakpoints on both chromosome 11 and chromosome 22. In 23 unrelated balanced-translocation carriers, the breakpoint was localized within a 400-kb interval between D22S788 (N41) and ZNF74, on 22q11. Also, 13 of these 23 carriers were tested with probes from chromosome 11, and, in each, the breakpoint was localized between D11S1340 and APOA1, on 11q23, to a region 相似文献   

Identification of rat cyclic nucleotide phosphodiesterase 11A (PDE11A): comparison of rat and human PDE11A splicing variants.

We have isolated and characterized rat cyclic nucleotide phosphodiesterase (PDE)11A, which exhibits properties of a dual-substrate PDE, and its splice variants (RNPDE11A2, RNPDE11A3, and RNPDE11A4). The deduced amino-acid sequence of the longest form of rat PDE11A splice variant, RNPDE11A4, was 94% identical with that of the human variant (HSPDE11A4). Rat PDE11A splice variants were expressed in a tissue-specific manner. RNPDE11A4 showed unique tissue distribution distinct from HSPDE11A4, which is specifically expressed in the prostate. Rat PDE11A splice variants were expressed in COS-7 cells, and their enzymatic characteristics were compared. Although the Km values for cAMP and cGMP were similar for all of them (1.3-1.6 and 2.1-3.9 microM, respectively), the Vmax values differed significantly (RNPDE11A4 > RNPDE11A2 > RNPDE11A3). Human PDE11A variants also displayed very similar Km values and significantly different Vmax values (HSPDE11A4 > HSPDE11A2 > HSPDE11A3 > HSPDE11A1). The Vmax values of HSPDE11A4 for cAMP and cGMP were at least 100 times higher than those of HSPDE11A1. These observations indicate unique characteristics of PDE11A splicing variants.     

Formation of mutually exclusive Rab11 complexes with members of the family of Rab11-interacting proteins regulates Rab11 endocytic targeting and function

Several Rabs, including Rab11, regulate the traffic and sorting of proteins in the endosomal pathway. Recently, six novel Rab11 family interacting proteins (FIPs) were identified. Although they share little overall sequence homology, all FIPs contain a conserved Rab11-binding domain. Here we investigate the role of FIPs as Rab11-targeting proteins and show that the Rab11-binding domain assumes an alpha-helical structure, with the conserved residues forming a hydrophobic Rab11-binding patch. This hydrophobic patch mediates the formation of mutually exclusive complexes between Rab11 and various members of FIP protein family. Furthermore, the formation of Rab11/FIP complexes regulates Rab11 localization by recruiting it to distinct endocytic compartments. Thus, we propose that Rab11/FIP complexes serve as targeting patches, regulating Rab11 localization and recruitment of additional cellular factors to different endocytic compartments.     

11β—羟基类固醇脱氢酶

现已发现两型１１β－羟基因固醇脱氢酶（１１β－ＨＳＤ）：１１β－ＨＳＤ１为氧化还原酶,催化皮质醇与其代谢产物之间的相互转化;１１β－ＨＳＤ２则为专一氧化酶,只催化皮质醇的失活。１１β－ＨＳＤ１在体内分布广泛,功能目前沿不清楚。１１β－ＨＳＤ２主要存在于盐皮质激素靶器官,肾脏１１β－ＨＳＤ２通过降解糖皮质激素保护盐皮质激素受体的特异性,肾脏此酶的缺乏,可以导致严重高血压。胎盘１１β－ＨＳＤ２通过降解     

Synthesis of 11C-radiopharmaceuticals using direct fixation of [11C]carbon dioxide and [11C]carbon monoxide

Synthesis of ¹¹C-labeled radiopharmaceuticals via direct fixation of [¹¹C]carbon dioxide and [¹¹C]carbon monoxide are described.     

Relationship of the human protooncogene CBL2 on 11q23 to the t(4;11), t(11;22), and t(11;14) breakpoints

A probe identifying CBL2, the human cellular homolog of the murine oncogene v-cbl and murine cellular protooncogene Cbl-2, and panels of rodent X human somatic cell hybrids were used to study the relationship of this protooncogene to translocations associated with acute leukemia, lymphoma, and Ewing sarcoma. CBL2 was mapped to 11q23 and found to translocate from chromosome 11 to 4 in an acute leukemia cell line possessing a t(4;11)(q21;q23) and from chromosome 11 to 14 in a B-cell lymphoma with a t(11;14)(q23;q32). In an Ewing sarcoma cell line with a t(11;22)(q23;q12), however, CBL2 remained on chromosome 11. Additional studies of other genes in the region of 11q23 allowed the following ordering of these genes and breakpoints: 11cen--q23--NCAM--CD3(E-D-G)--[t(11;14), t(4;11)]--(THY1, CBL2, ETS1)--t(11;22)--11qter. The gross structure of the CBL2 sequences examined was not altered by either of the flanking breakpoints. Given that the 5' and 3' ends of the CBL2 gene are not known and are probably not evaluated by the v-cbl probe, these results do not rule out the possibility of CBL2 involvement in the pathogenesis of a subset of acute leukemias possessing a t(4;11), B-cell lymphomas possessing a t(11;14), or Ewing sarcomas possessing a t(11;22).     

Hoxa11 and hoxd11 regulate chondrocyte differentiation upstream of runx2 and shox2 in mice

During limb development, posterior Hox genes of the Hoxa- and Hoxd cluster provide positional information along the limb axis. Here we report a new function for Hoxa11 and Hoxd11 in regulating the early steps of chondrocyte differentiation. We analyzed forelimbs of Hoxa11(-/-);d11(-/-) and Ulnaless mice, which are characterized by specifically shortened zeugopods. By detailed morphological and molecular analyses, we show that loss of Hoxa11 and Hoxd11 in the ulna of both mutants leads to an arrest of chondrocyte differentiation at a step before the separation into round and columnar cells takes place. Furthermore, we demonstrate that Hoxa11 and Hoxd11 act upstream of Runx2 and Shox2, two key regulators of chondrocyte differentiation. We hypothesize that Runx2 activates Shox2 in early chondrocytes, which at later stages induces Runx2 expression to regulate hypertrophic differentiation. These results give insight into mechanisms by which positional information might be translated into a specific bone pattern.     

Paracentric inversion 11

A new familial case of paracentric inversion of chromosome 11 inv(11)(q21q23.3) ascertained by multiple abortions in a female carrier is presented. A review of the literature shows 19 further cases of paracentric inversion 11. According to the different breakpoints, the inversions of the long arm of chromosome 11 may be classified into three types.     

Partial trisomy 11q and familial translocation 11--22 (author's transl)]

By heat denaturation, a reciprocal translocation was found in the mother of two malformed sibs. In her 46,XX,t(11 ;22)(q23 ;q11) caryotype, the rearranged elements exhibit no change of length. The 2 sibs are trisomic for the distal part of the long arm of chromosome 11.     

GRAB is a binding partner for the Rab11a and Rab11b GTPases

Co-ordination of Rab GTPase function has emerged as a crucial mechanism in the control of intracellular trafficking processes in eukaryotic cells. Here, we show that GRAB/Rab3IL1 [guanine nucleotide exchange factor for Rab3A; RAB3A interacting protein (rabin3)-like 1], a protein that has previously be shown to act as a GEF (guanine nucleotide exchange factor) for Rab3a, Rab8a and Rab8b, is also a binding partner for Rab11a and Rab11b, but not the closely related Rab25 GTPase. We demonstrate that exogenous expression of Rab11a and Rab11b shift GRAB’s distribution from the cytoplasm onto membranes. We find that the Rab11a/Rab11b-binding region of GRAB lies within its carboxy-terminus, a region distinct from its GEF domain and Rab3a-binding region. Finally, we describe a GRAB deletion mutant (GRAB_Δ223–228) that is deficient in Rab11-binding ability. These data identify GRAB as a dual Rab-binding protein that could potentially link Rab3 and Rab11 and/or Rab8 and Rab11-mediated intracellular trafficking processes.