Syntheses of nucleic acids are of importance not only in the natural product chemistry but also in the molecular recognition study in biology. This review describes syntheses of RNA and DNA, which were found to be related each other. Deoxyinosine probes were developed for cloning genes with degenerated codons. Synthetic genes for c-Ha-ras and T4 endonuclease V provided new approaches in recognition of nucleic acids by proteins. Antibodies specific for photo-damaged pyrimidines in DNA have been studied by cloning and mutating their genes.
This review summarizes our studies on the molecular biology of prostaglandin (PG) receptors and L-histidine decarboxylase (HDC). Regarding PG receptors, we have cloned five basic PG receptors (DP, EP, FP, IP, TP) and four EP subtypes (EP1-EP4). The PG receptors are divided into three families related to signal transduction systems of the receptors; Gs-couple group (IP, DP, EP2 and EP4), Gq-couple group (TP, FP and EP1), and Gi-couple group (EP3 and its isoform). EP3 isoforms having different C-terminal peptides can couple to distinct G proteins (Gi, Gs, Gq). Tissue specific expression of EP subtype mRNAs was observed in various organs. The phenotypic changes of mice deficient in each receptor are; the abnormal labor in FP-deficient mice, the failure of febrile response in EP3-deficient mice, the abnormal closure of ductus arteriosus after birth in EP4-deficient mice, and the impaired inflammatory swelling and pain responses in IP-deficient mice. Regarding HDC, we have purified mouse HDC from mastocytoma cells, which is a dimer of 53 kDa subunit, and then cloned its cDNA. The size of a cDNA-deduced HDC is 74 kDa. In the rat mast cell line, the endogenous 74 kDa form of HDC was translated in the cytosol and then translocated to the ER, where it was post-translationally processed to the 53 kDa form. On the other hand, the cytosolic 74 kDa form was rapidly degraded by an ATP/ubiquitin-dependent proteasome system. The 74 kDa form without on N-terminal signal sequence is inserted into the ER membrane with a C-terminal segment.
Nonnative English speakers writing technical papers in English are challenged by the perplexing usage and expressions of English common to scientific journals. This paper will focus on the use of articles, the position of adverbs, the expressions related to 'cause and reason', and the use of prepositions. Unlike peer literature intended to facilitate nonnative's technical English writing ability, the author has developed a highly practical, quantitative approach to technical or pharmaceutical English. Computer technology was applied to statistically analyze the frequency and the probabilities of English usage and expressions found in the Journal of Biological Chemistry (J.B.C.), 1994 and the Journal of Organic Chemistry (J.O.C.), 1987. Expressions and usage used more frequently indicate greater acceptance and generality for technical English writing, while the degree of probability characterizes English usage. Comparing the attributes of English between the two journals revealed considerable similarities and appreciable differences inherent in each scientific specialty. It is proposed that the quantitative method developed for this study can contribute to various fields of English language research.
A newly developed fluorescence detector cell for capillary electrophoresis was described. Detection of analytes having fluorescence is performed in an on-capillary mode with a xenon arc lamp. A grating monochromator was used for the selection of the excitation wavelength. Fluorescence emission was monitored by collection of light from the capillary using a newly devised detector cell positioned at right angle to the excitation beam. Emission wavelengths were isolated using a filter and amplified with a photomultiplier. The detection limits obtained using the newly devised detector cell for amino acids and carbohydrates labeled with a fluorescent reagent were compared with that obtained using a conventional quartz detector cell. The results indicated that 100 nM and 4 μM of amino acids and oligosaccharides labeled with 9-fluorenymethyl chloro- formate and 2-aminopyridine, respectively, could be detected with the newly devised detector cell, in contrast to no signals with the conventional quartz detector cell. The separation and detection of fluorescent derivatives of amino acids, peptides, monosaccharides and oligosaccharides were also performed and an appropriate linearity was observed in a detector response of the samples within the constant concentration.
The methods for the isolation and purification of iodoglycyltyrosines [glycyl-3-iodotyrosine (Gly-MIT) and glycyl-3, 5-diiodotyrosine (Gly-DIT)] from a reaction mixture were examined by the use of high-performance liquid chromatography (HPLC). Glycyltyrosine (Gly-Tyr) was iodinated with iodine monochloride (ICl)(the molar ratio of Gly-Tyr to ICl was 1 : 1.5) in 0.1 M NaOH. The synthesized Gly-MIT and Gly-DIT were separated on a μBondapak C18 column employing stepwise gradient systems of a 0.1% trifluoroacetic acid/acetonitrile mixture and a water/acetonitrile mixture. Chemically pure Gly-MIT and Gly-DIT were obtained in 30.2% and 28.2% yields, respectively.