Laser-induced fluorescence and one- and two-color, mass- selected R2PI excitation spectra of the S1 ← S0 electronic transitions in 2-phenylethyl alcohol and 2-phenylethylamine have been recorded in a jet-cooled environment. Five conformers of 2-phenylethyl alcohol and four of 2-phenylethylamine have been identified, together with a number of 1:1 hydrated water clusters. The fifth origin band in the excitation spectrum of 2-phenylethylamine has been reassigned to a water cluster, primarily on the basis of its ion fragmentation pattern. Analysis of their partially resolved rotational band contours has been aided by ab initio molecular orbital calculations, conducted at levels of theory ranging from MP2/3-21G* to MP2/6-311G** for the ground state and CIS/6-311G** for the first electronically excited singlet state. The reliability of the CIS method has also been tested through benchmark calculations, including computations on a related, experimentally known conformational system, methyl 3-hydroxybenzoate. 2-Phenylethylamine and 2-phenylethyl alcohol both display anti and gauche conformations (distinguished by their orientation about the Cα−Cβ bond) but the folded, gauche conformations, which allow the terminal hydroxyl or amino hydrogen atoms to be hydrogen bonded to the aromatic ring, are found to be the most stable. Their intramolecular binding energies are ∼5.5 kJ mol-1. The anti conformers display b-type rotational band contours, reflecting the 1Lb character of their first excited singlet states. In contrast, the band contours of the gauche conformers display a hybrid character, which reflects a strong rotation of the electronic transition moment in the molecular frame, attributed to electronic state mixing. The rotation of the transition moment is strongly modulated by the binding of a water molecule to the folded molecular conformer and, in the bare molecule, by changes in the orientation of the terminal hydroxyl or amino group. This effect allows a ready distinction to be made between the hydrogen-bonded and the non- hydrogen-bonded gauche conformers.

SUMMARYSynthesis of cellular protein was substantially inhibited within I h of infection with herpes simplex virus, type 2, strain G (HSV-2). The inhibition also occurred, although no virus-specific protein synthesis was detected, after infection with u.v. irradiated virus and in cytoplasts that had been enucleated before infection. The inhibitory activity could not be distinguished from infectivity by dilution, sedimentation or reaction with y-globulin. HSV-2 also suppressed the synthesis of Sendal virus proteins, but not those specified by HSV-I.Host protein synthesis was no more sensitive than virus protein synthesis to an increased concentration of NaCI in the medium, nor could the suppression of host synthesis be prevented by adding excess MgC12 to the medium or by omitting CaC12 or NaCI. It was accompanied by the breakdown of polyribosomes, which also occurred in the presence of cycloheximide but not at 4 °C. The breakdown yielded ribosomes that were sensitive to a high salt concentration, unlike those produced by treatment of polyribosomes with RNase. The synthesis of cellular DNA and RNA was also inhibited following infection with u.v.-inactivated virus.It is concluded that the suppression of host protein synthesis (and probably also of host DNA and RNA synthesis) is caused by a constituent of the infecting virus particles. The mechanism is obscure but probably does not depend on the leakage out of the cell of Mg ~+ or into the cell of Ca 2+ or Na + ions, nor on the specific inhibition of initiation of host polypeptide chains, nor on RNase-like attack on host polyribosomes.

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SUMMARYIn cells infected with herpes simplex virus, HSV-I, newly synthesized polypeptides accumulated in the nucleus at different rates, which did not change during the first 6 h after infection. Canavanine, an arginine analogue, prevented the nuclear accumulation of ICP (infected cell polypeptides) 5 and 8, and azetidine, a proline analogue, prevented that of ICP 5 and 7. The transfer of polypeptides to the nucleus was inhibited at 4 °C but not by dinitrophenol. Some of the nuclear polypeptides could be released by washing isolated nuclei with hypertonic salt solutions. ICP I7 was particularly sensitive to high salt treatment while ICP 5 and I I were resistant. ICP 4 b, a modified form of the ~ polypeptide ICP 4, was released by EDTA, and the detergent NP4o removed ICP I I. Treatment of nuclei with DNase selectively reduced the amount of bound -polypeptides ICP 4 c (the second modified form of ICP 4), o and 27 as well as ICP 8 and 25. Nuclei isolated from infected or uninfected cells and incubated in labelled cytoplasmic extracts took up primarily ICP 8 and 32. Alpha polypeptides were taken up to a lesser extent and ICP 6 and IO were excluded. It is concluded that affinities for various constituents of host cell nuclei are likely to determine the nuclear accumulation of specific virus polypeptides.