1H-, 13C-, and 113Cd-nmr study of the Cd(II) complex of a blocked peptide,Z-Cys-Ala-Pro-His-OMe,in organic solvents

The Cd(II) complex of a peptide, Z-Cys-Ala-Pro-His-OMe was prepared and characterized by absorption, CD, ¹H-, ¹³C-, and ¹¹³Cd-nmr, and nuclear Overhauser effect spectroscopy (NOESY) spectra to show the coordination of cysteine thiolate and histidine imizazole to Cd(II) ion. The NOESY spectra in dimethyl formamide showed that the cysteine residue was in proximity to the histidine residue. These results reveal the dictation of Z-Cys-Ala-Pro-His-OMe to Cd(II) ion in solution. Temperature-dependent dissociation equilibrium of histidine imidazole in solution was observed in this complex. Structural features of the chelating peptide are discussed. © 1995 John Wiley & Sons, Inc.     

Mutational analysis of human immunodeficiency virus type 1 (HIV-1) accessory genes: requirement of a site in the nef gene for HIV-1 replication in activated CD4+ T cells in vitro and in vivo.

Human immunodeficiency virus type 1 (HIV-1) accessory genes including nef, vif, and vpr are important factors that determine the replication and pathogenesis of HIV-1. The state of activation is also important for the replication of HIV-1. We evaluated the properties of nef-, vif-, and vpr-minus macrophage-tropic HIV-1(JR) CSF in primary CD4+ Th1- or Th2-like cell cultures which had been activated through CD3 molecules in the presence of interleukin-2 (IL-2) and IL-12 (Th1-like culture) or IL-4 (Th2-like culture), respectively. In activated Th1- or Th2-like cultures, replication of nef-minus HIV-1(JR-CSF) was markedly lower than that of wild-type HIV-1. Subsequent analysis by site-directed mutagenesis showed that (i) the presence of an acidic amino acid-rich domain (amino acid residues 72 to 75) in the Nef protein was critical for the enhancement of viral DNA synthesis, resulting in increased virus growth rate, and (ii) prolines that form part of Src homology 3 binding domain were not essential for viral replication. We also confirmed the importance of sites by using an HIV-1-infected animal model, the hu-PBL-SCID mouse system, representing HIV-1 replication and pathogenesis in activated CD4+ T cells in vivo. These results indicate that Nef accelerates viral replication in activated CD4+ T cells.     

Alcohol and aldehyde dehydrogenase genotypes and drinking behavior of Chinese living in Shanghai

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), the principal enzymes responsible for oxidative metabolism of ethanol, exist in multiple, genetically determined molecular forms. Widely different kinetic properties in some of these isozymes account for the individual differences in alcohol sensitivity. In this study we used the polymerase chain reaction/restriction fragment length polymorphism method to determine the genotypes of the ADH2 and ALDH2 loci of alcoholic and nonalcoholic Chinese living in Shanghai. We also investigated the subjects' drinking patterns by means of semistructured interviews. The alcoholics had significantly lower frequencies of the ADH2² and ALDH2² alleles than did the nonalcoholics, suggesting the inhibitory effects of these alleles for the development of alcoholism. In the nonalcoholic subjects, ADH2² had little, if any, effect, despite the significant effect of the ALDH2² allele in decreasing the alcohol consumption of the individual. Taken together, these results fit the proposed hypothesis for the development of alcoholism, i.e., drinking behavior is greatly influenced by the individual's gentoypes of alcohol-metabolizing enzymes, and the risk of becoming alcoholic is proportionate with the ethanol consumption of the individual.     

High-resolution solution structure of siamycin II: Novel amphipathic character of a 21-residue peptide that inhibits HIV fusion

Summary The 21-amino acid peptides siamycin II (BMY-29303) and siamycin I (BMY-29304), derived from Streptomyces strains AA3891 and AA6532, respectively, have been found to inhibit HIV-1 fusion and viral replication in cell culture. The primary sequence of siamycin II is CLGIGSCNDFAGCGYAIVCFW. Siamycin I differs by only one amino acid; it has a valine residue at position 4. In both peptides, disulfide bonds link Cys¹ with Cys¹³ and Cys⁷ with Cys¹⁹, and the side chain of Asp⁹ forms an amide bond with the N-terminus. Siamycin II, when dissolved in a 50:50 mixture of DMSO and H₂O, yields NOESY spectra with exceptional numbers of cross peaks for a peptide of this size. We have used 335 NOE distance constraints and 13 dihedral angle constraints to generate an ensemble of 30 siamycin II structures; these have average backbone atom and all heavy atom rmsd values to the mean coordinates of 0.24 and 0.52 Å, respectively. The peptide displays an unusual wedge-shaped structure, with one face being predominantly hydrophobic and the other being predominantly hydrophilic. Chemical shift and NOE data show that the siamycin I structure is essentially identical to siamycin II. These peptides may act by preventing oligomerization of the HIV transmembrane glycoprotein gp41, or by interfering with interactions between gp41 and the envelope glycoprotein gp120, the cell membrane or membrane-bound proteins [Frèchet, D. et al. (1994) Biochemistry, 33, 42–50]. The amphipathic nature of siamycin II and siamycin I suggests that a polar (or apolar) site on the target protein may be masked by the apolar (or polar) face of the peptide upon peptide/protein complexation.Abbreviations ABNR adopted basis Newton Raphson - AIDS acquired immunodeficiency syndrome - CW continuous wave - DMSO dimethylsulfoxide - DQF-COSY two-dimensional double-quantum-filtered correlation spectroscopy - HIV human immunodeficiency virus - HSQC heteronuclear single-quantum coherence - NOE nuclear Overhauser enhancement - NOESY two-dimensional nuclear Overhauser enhancement spectroscopy - ppm parts per million - P.E.-COSY two-dimensional primitive exclusive correlation spectroscopy - REDAC redundant dihedral angle constraint - rf radio frequency - rmsd root-mean-square difference - SIV simian immunodeficiency virus - sw spectral width - _m mixing time - TOCSY two-dimensional total correlation spectroscopy - TSP trimethylsilyl-2,2,3,3-²H₄-propionate - 2D two-dimensional     

Bacterial Plasmids in Antarctic Natural Microbial Assemblages

Samples of psychrophilic and psychrotrophic bacteria were collected from sea ice, seawater, sediments, and benthic or ice-associated animals in McMurdo Sound, Antarctica. A total of 155 strains were isolated and tested for the presence of plasmids by DNA agarose gel electrophoresis. Thirty-one percent of the isolates carried at least one kind of plasmid. Bacterial isolates taken from sediments showed the highest plasmid incidence (42%), and isolates from seawater showed the lowest plasmid incidence (20%). Plasmids were significantly more frequent in the strains which had been first isolated from low-nutrient media (46%) than in the strains which had been isolated from high-nutrient media (25%). Multiple forms of plasmids were observed in two-thirds of the plasmid-carrying strains. A majority of the plasmids detected were estimated to have a mass of 10 megadaltons or less. Among 48 plasmid-carrying strains, 7 showed antibiotic resistance. It is concluded that bacterial plasmids are ubiquitous in natural microbial assemblages of the pristine marine ecosystem of Antarctica.     

Partial tetrasomy 9(9pter to 9q2101) due to an extra iso-dicentric chromosome.

A 3-year-old boy with partial No. 9 tetrasomy is described. The patient showed markedly retarded physical and mental development as well as multiple congenital anomalies. Routine chromosome analysis revealed an extra C-group chromosome. It had a pronounced secondary constriction at the proximal part of its long arm. Based on studies by a variety of banding techniques, the extra chromosome was identified to be an iso-dicentric No. 9 chromosome with inactivation of one of the two centromeres, the karyotype being 47,XY, + DIC (9)(Q2101). The value of BrdUrd treatment was emphasized in the detection of a very small piece of euchromatin within a long stretch of constitutive heterochromatin.     

Effects of taurine and γ-aminobutyric acid on akinesia and analgesia induced by D-Ala2-Met-enkephalinamide in rats

Effects of taurine or γ-aminobutyric acid (GABA) on akinesia and analgesia induced by D-Ala²-Met-enkephalinamide were investigated in rats. Administration of taurine (dose range: 2.375×10^?2 M–9.5×10^?2 M/10 μl) into the left lateral ventricle 10 min prior to the injection of D-Ala²-Met-enkephalinamide (50 μg/10 μl) produced a dose-dependent reduction in the duration of akinesia and to some extent of analgesia, as estimated at 30 min and 60 min following the enkephalinamide injection; at the first estimation-time (10 min), taurine did not alter the duration of akinesia or that of analgesia. The median effective dose (ED₅₀) for akinesia determined at 60 min after D-Ala²-Met-enkephalinamide was 5 times greater and that for analgesia assessed at the same time was 1.7 times greater in taurine-treated rats than the respective doses in control animals. Administration of GABA under similar experimental conditions produced a dose-dependent reduction in the duration of analgesia from the initial estimation time (10 min) following the injection of D-Ala²-Met-enkephalinamide. The ED₅₀ for analgesia determined at 30 min after D-Ala²-Met-enkephalinamide was 3 times greater in GABA-treated rats than in control animals. Unlike the effects of taurine, GABA did not alter the duration of akinesia. Neither the duration of akinesia nor that of analgesia was modified by taurine or GABA alone in rats tested 9 min after the injection of each amino acid. These findings suggest that taurine may promote a recovery from both akinesia and analgesia, while GABA decreases only the analgesia induced by D-Ala²-Met-enkephalinamide.     

Growth-related changes in color and sex inHalichoeres poecilopterus

Coloration and sex change were studied in a temperate wrasseHalichoeres poecilopterus in the central part of the Seto Inland Sea, Japan. 1,270 examples, 45–179 mm SL, were collected from May to December both in 1983 and 1984. The species is a diandric, protogynous hermaphrodite, and has three color patterns: pale color type (A), brilliant color type (B) and intermediate color type (AB). A-fish were less than 142 mm SL and consisted of primary males (42.6%), females (55.4%), secondary males (0.3%) and fish with transitional gonads (1.7%). A-females changed their color to B, through AB, in the size range 101–131 mm SL. A-primary males changed their color to B, through AB, in the size range 103–134 mm SL. B-fish consisted of primary males (38.6%), secondary males (54.6%) and fish with transitional gonads (6.8%). The majority of females changed their sex to male in the size range 98–131 mm SL.     

Production of beta-carotene in Zymomonas mobilis and Agrobacterium tumefaciens by introduction of the biosynthesis genes from Erwinia uredovora.

The Erwinia uredovora crtB, crtE, crtI, and crtY genes required for beta-carotene biosynthesis were introduced by conjugal transfer into an ethanol-producing bacterium, Zymomonas mobilis, and a phytopathogenic bacterium, Agrobacterium tumefaciens, in which no carotenoid is synthesized. The transconjugants of Z. mobilis and A. tumefaciens carrying these genes appeared as yellow colonies and produced 220 and 350 micrograms of beta-carotene per g of dry weight, respectively, in the stationary phase in liquid culture.     

Verbascoside production by plant cell cultures

Verbascoside was found to be produced in all calli derived from eleven species that contained the compound in their leaves. Cell suspension cultures were also established in three species, i.e., Leucosceptrum japonicum f. barbinerve, Syringa josikaea, and Sy. vulgaris, all of which were found to produce verbascoside at more than 1 g/l. Of the three species, suspension cultures of L. japonicum f. barbinerve showed rapid growth and the highest yield of verbascoside (1.89 g/l). In these cultures, the effects of major salt concentration in B5 medium on cell growth and verbascoside production were examined. Maximum cell growth and maximum verbascoside production were both achieved by reducing the major salt concentration to half that of the original medium.