Identification of two novel clusters of ultrahigh-sulfur keratin-associated protein genes on human chromosome 11

We analyzed two novel clusters of keratin-associated protein (KAP) genes on human chromosome 11 (11p15.5 and 11q13.5) in which we identified two known human KRTAP5 genes, KerA (=KRN1) and KerB, and nine novel KRTAP5 family genes. RT-PCR analysis of these KAP genes showed preferential expression in human hair root, suggesting these gene products are required for hair formation. Based on the deduced amino acid sequences, all these KAP proteins were classified into an ultrahigh-sulfur (UHS) type KAP with high cysteine content (> 30 mol%). These KAPs also showed high glycine and serine contents (average 24.30 and 21.13 mol%, respectively), distinguishing from other UHS/HS KAP families located on human chromosomes 17 and 21. Dot-matrix analysis revealed a significant similarity between these two KAP gene clusters. We postulated a mechanism by which these two KAP gene clusters are generated via genomic duplication of a primordial gene cluster followed by genetic modification during evolution.     

The role of the helper lipid dioleoylphosphatidylethanolamine (DOPE) for DNA transfection cooperating with a cationic lipid bearing ethylenediamine

Gene therapy is expected to treat various incurable diseases including viral infections, autoimmune disorders, and cancers. Cationic lipids (CL) have been used as carriers of therapeutic DNAs for gene therapy because they can form a complex with DNA and such a complex can be incorporated into cells and transport the bound DNA to cytosol. The CL/DNA complexes are called lipoplexes and categorized as a non-viral vector. Lipoplexes are often prepared by adding a neutral phospholipid dioleoylphosphatidylethanolamine (DOPE) to CL in order to enhance transfection. However, the role of DOPE is not fully understood. We synthesized a new CL having an ethylenediamine cationic head group, denoted by DA, and found that addition of DOPE to DA achieved a good efficiency, almost in the similar level of commonly used transfection reagent Lipofectamine 2000 (Invitrogen). The composition of DA:DOPE = 1:1 showed the highest efficiency. This lipoplex showed structural transition when pH was changed from 7 to 4, corresponding pH lowering in late endosome, while DOPE itself showed structural transition at more basic pH around 8. The present data showed that the DOPE/DA composition determines the structural transition pH and choosing a suitable pH, i.e., a suitable composition, is essential to increase the transfection efficiency.     

Preparation of a fluorescent derivative of benzoylecgonine, and preliminary studies of its application to the analysis of urine

A sensitive high-performance liquid chromatographic method using 3-bromomethyl-6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone (Br-DMEQ) as a fluorescent labeling reagent is described for the determination of benzoylecgonine (BE) and ecgonine (EC). The Br-DMEQ derivatives of BE and EC were separated on a C₁₈ column and detected at 455 nm with excitation at 370 nm. The detection limits of the proposed method were 18.7 fmol for BE and 12.5 pmol for EC at a signal-to-noise ratio of 3. Relative standard deviations of five replicate measurements were 1.94% (10 pmol) and 2.98% (50 pmol) for BE and 6.3% (250 pmol) and 5.62% (1.25 pmol) for EC. This method was applied to the determination of BE in human urine. BE was extracted from urine by solvent extraction with chloroform—isopropyl alcohol (9:1, v/v) solution. Levels of 2.5 · 10⁻⁸ M BE in urine (25 pmol/ml) could be determined.     

Low-temperature-induced structural changes in human lysozyme elucidated by three-dimensional NMR spectroscopy

The three-dimensional solution structures of human lysozyme were determined at 35 and 4 degrees C using the heteronuclear multidimensional NMR spectroscopy, which were compared with each other to clarify the structural response of this enzyme to lowering of the temperature. Together with the data of the temperature dependence experiments of the lytic activity against Micrococcus luteus, we consider the implication of the observed structural change for the low-temperature-induced reduction of the activity of human lysozyme. The structures of human lysozyme determined at the two temperatures are found to be similar, both of which comprise four alpha-helices (A- to D-helices) and three antiparallel beta-strands (beta(1)-beta(3)), leading to the constructions of the alpha- and beta-domains as previously identified in the X-ray crystal structure. A significant structural change was observed for the "active site lobe" comprising the loop region connecting C- and D-helices and the following D-helix, which moves toward the active site cleft located between the alpha- and beta-domains so as to obstruct the cleft according to the temperature lowering. It further appeared that the total volume as well as the accessible surface area of human lysozyme decreases with lowering of the temperature, suggesting that the internal cavity of this enzyme shrinks under low temperature environment. Because in human lysozyme the region comprising the active site lobe is responsible for turnover of the enzymatic reaction against the substrate, the low-temperature-induced structural change of the active site lobe presumably controls the efficiency of the lytic activity under low temperatures.     

The B cell inhibitory Fc receptor triggers apoptosis by a novel c-Abl family kinase-dependent pathway

The inhibitory Fc receptors function to regulate the antigen-driven activation and expansion of lymphocytes. In B cells, the Fc gammaRIIB1 is a potent inhibitor of B cell antigen receptor (BCR) signaling when coligated to the BCR by engagement of antigen-containing immune complexes. Inhibition is mediated by the recruitment of the inositol phosphatase, SHIP, to the Fc gammaRIIB1 phosphorylated tyrosine-based inhibitory motif (ITIM). Here we show that BCR-independent aggregation of the Fc gammaRIIB1 transduces an ITIM- and SHIP-independent proapoptotic signal that is dependent on members of the c-Abl tyrosine kinase family. These results define a novel Abl family kinase-dependent Fc gammaRIIB1 signaling pathway that functions independently of the BCR in controlling antigen-driven B cell responses.     

Acute effect of static stretching on power output during concentric dynamic constant external resistance leg extension

The purpose of the present study was to clarify the effect of static stretching on muscular performance during concentric isotonic (dynamic constant external resistance [DCER]) muscle actions under various loads. Concentric DCER leg extension power outputs were assessed in 12 healthy male subjects after 2 types of pretreatment. The pretreatments included (a) static stretching treatment performing 6 types of static stretching on leg extensors (4 sets of 30 seconds each with 20-second rest periods; total duration 20 minutes) and (b) nonstretching treatment by resting for 20 minutes in a sitting position. Loads during assessment of the power output were set to 5, 30, and 60% of the maximum voluntary contractile (MVC) torque with isometric leg extension in each subject. The peak power output following the static stretching treatment was significantly (p < 0.05) lower than that following the nonstretching treatment under each load (5% MVC, 418.0 +/- 82.2 W vs. 466.2 +/- 89.5 W; 30% MVC, 506.4 +/- 82.8 W vs. 536.4 +/- 97.0 W; 60% MVC, 478.6 +/- 77.5 W vs. 523.8 +/- 97.8 W). The present study demonstrated that relatively extensive static stretching significantly reduces power output with concentric DCER muscle actions under various loads. Common power activities are carried out by DCER muscle actions under various loads. Therefore, the result of the present study suggests that relatively extensive static stretching decreases power performance.     

Modification of a novel angiogenic peptide, AG30, for the development of novel therapeutic agents

We previously identified a novel angiogenic peptide, AG30, with antibacterial effects that could serve as a foundation molecule for the design of wound-healing drugs. Toward clinical application, in this study we have developed a modified version of the AG30 peptide characterized by improved antibacterial and angiogenic action, thus establishing a lead compound for a feasibility study. Because AG30 has an α-helix structure with a number of hydrophobic and cationic amino acids, we designed a modified AG30 peptide by replacing several of the amino acids. The replacement of cationic amino acids (yielding a new molecule, AG30/5C), but not hydrophobic amino acids, increased both the angiogenic and the antimicrobial properties of the peptide. AG30/5C was also effective against methicillin-resistant Staphylococcus aureus (MRSA) and antibiotic-resistant Pseudomonas aeruginosa. In a diabetic mouse wound-healing model, the topical application of AG30/5C accelerated wound healing with increased angiogenesis and attenuated MRSA infection. To facilitate the eventual clinical investigation/application of these compounds, we developed a large-scale procedure for the synthesis of AG30/5C that employed the conventional solution method and met Good Manufacturing Practice guidelines. In the evaluation of stability of this peptide in saline solution, RP-HPLC analysis revealed that AG30/5C was fairly stable under 5°C for 12 months. Therefore, we propose the use of AG30/5C as a wound-healing drug with antibacterial and angiogenic actions.     

Loss of aPKCλ in Differentiated Neurons Disrupts the Polarity Complex but Does Not Induce Obvious Neuronal Loss or Disorientation in Mouse Brains

Cell polarity plays a critical role in neuronal differentiation during development of the central nervous system (CNS). Recent studies have established the significance of atypical protein kinase C (aPKC) and its interacting partners, which include PAR-3, PAR-6 and Lgl, in regulating cell polarization during neuronal differentiation. However, their roles in neuronal maintenance after CNS development remain unclear. Here we performed conditional deletion of aPKCλ, a major aPKC isoform in the brain, in differentiated neurons of mice by camk2a-cre or synapsinI-cre mediated gene targeting. We found significant reduction of aPKCλ and total aPKCs in the adult mouse brains. The aPKCλ deletion also reduced PAR-6β, possibly by its destabilization, whereas expression of other related proteins such as PAR-3 and Lgl-1 was unaffected. Biochemical analyses suggested that a significant fraction of aPKCλ formed a protein complex with PAR-6β and Lgl-1 in the brain lysates, which was disrupted by the aPKCλ deletion. Notably, the aPKCλ deletion mice did not show apparent cell loss/degeneration in the brain. In addition, neuronal orientation/distribution seemed to be unaffected. Thus, despite the polarity complex disruption, neuronal deletion of aPKCλ does not induce obvious cell loss or disorientation in mouse brains after cell differentiation.     

Cloning and Functional Expression of a Novel Geranylgeranyl Pyrophosphate Synthase Gene from Arabidopsis thaliana in Escherichia coli

A gene encoding a novel geranylgeranyl pyrophosphate (GGPP)synthase from Arabidopsis thaliana has been identified and termedGGPS5. The gene has been sequenced and expressed in Escherichiacoli. The deduced amino acid sequence showed 64.5% and 57.5%identity with a putative GGPP synthase from Arabidopsis andCapsicum annuum, respectively. GGPP enzymatic activity was detectedin E. coli cells expressing the GGPS5 gene in two differentways. One was the direct measurement of GGPP synthase activityin cell extracts and the other was the yellow color productionof cells when the GGPS5 gene was co-expressed with crtB, crtI,crtX, crtY and crtZ genes derived from Erwinia uredovora. (Received May 20, 1996; Accepted December 14, 1996)