Occurrence of multiple forms of alcohol dehydrogenase in Penicillium supplemented with 2,3-butanediol

The NAD-dependent oxidation of ethanol, 2,3-butanediol, and other primary and secondary alcohols, catalyzed by alcohol dehydrogenases derived from Penicillium charlesii, was investigated. Alcohol dehydrogenase, ADH-I, was purified to homogeneity in a yield of 54%. The enzyme utilizes several primary alcohols as substrates, with K_m values of the order of 10^?4m. A K_m value of 60 mm was obtained for R,R,-2,3-butanediol. The stereospecificity of the oxidation of 2-butanol was investigated, and S-(+)-2-butanol was found to be oxidized 2.4 times faster than was R-(?)-2-butanol. The reduction of 2-butanone was shown to produce S-(+)-2-butanol and R-(?)-butanol in a ratio of 7:3. ADH-I is the primary isozyme of alcohol dehydrogenase present in cultures utilizing glucose as the sole carbon source. The level of alcohol dehydrogenase activity increased 7.6-fold in mycelia from cultures grown with glucose and 2,3-butanediol (0.5%) as carbon sources compared with the activity in cultures grown on only glucose. Two additional forms of alcohol dehydrogenase, ADH-II and ADH-III, were present in the cultures supplemented with 2,3-butanediol. These forms of alcohol dehydrogenase catalyze the oxidation of ethanol and 2,3-butanediol. These data suggest that P. charlesii carries out an oxidation of 2,3-butanediol which may constitute the first reaction in the degradation of 2,3-butanediol as well as the last reaction in the mixed-acid fermentation. Alcohol dehydrogenase activities in P. charlesii may be encoded by multiple genes, one which is expressed constitutively and others whose expression is inducible by 2,3-butanediol.     

The glycoprotein 71 of ecotropic Friend murine leukemia virus. Structure of the oligosaccharides linked to asparagine-12

The glycoprotein from Friend murine leukemia virus was digested with protease from Staphylococcus aureus V8. A glycopeptide comprising the N-terminal glycosylation site (Asn-12) was isolated from the mixture of fragments and analyzed by amino acid sequencing and methylation-capillary gas chromatography-mass spectrometry before and after treatment with sialidase from Vibrio cholerae. Asn-12 was thus found to be substituted by a family of partially sialylated, fucosylated, and intersected glycoprotein N-glycans of the hybrid type.     

High resolution microanalysis for phosphorus in Golgi complex beads of insect fat body tissue by electron spectroscopic imaging

Golgi complex beads are 10 nm particles arranged in rings on the smooth forming face of the Golgi complex that stain specifically with bismuth in arthropod cells. In vitro experiments with biological molecules spotted on to cellulose acetate strips indicated that bismuth bound to the beads through phosphate groups. We could detect a weak phosphorus signal from the beads using a new technique called electron spectroscopic imaging that is capable of very high spatial resolution (0.3–0.5 nm) and sensitivity (50 atoms of phosphorus). Detection was not obscured by tissue staining with bismuth or uranyl acetate or by using an inorganic buffer (Na cacodylate). Localization of phosphorus was greatly improved by using colour-enhanced computer pictures of the electron spectroscopic images and quantitating the images. The results indicate that the phosphorus content of the beads is large enough to account for their bismuth reactivity.     

Mass spectrometry of silylated flavonol O-glycosides

The electron impact mass spectra of 19 trimethyl silylated flavonol mono-, di- and -triglycosides are reported for the first time. All spectra show wel     

Bacteriophage MS2 RNA: A correlation between the stability of the codon: Anticodon interaction and the choice of code words

Summary The non-random distribution of degenerate code words in Bacteriophage MS2 RNA can be explained partially by considerations of the stability of the codon-anticodon complex in prokaryotic systems. Supporting this hypothesis we note that wobble codons are positively selected in codons having G and/or C in the first two positions. In contrast, wobble codons are statitically less likely in codons composed of A and U in the first two positions. Analyses of nucleotides adjacent to 5 and 3 ends of codons indicate a nonrandom distribution as well. It is thus likely that some elements of RNA evolution are independent of the structural needs of the RNA itself and of the translated protein product.This work was supported by grants from the Belgian Government Actions concertées - Gekon-certéerde Acties, N.F.W.O. and F.K.F.O. as well as from le Ministère de l'éducation du Québec. A preliminary report of this work was given at the EMBO ribosome workshop, Brussels 1976     

Chromatographic resolution of amino acid adducts of aliphatic halides

Numerous xenobiotics are known to be bioactivated and to covalently bind to proteins, but the resulting amino acid adducts (AAAs) are unknown. In this study the AAAs of twelve ¹⁴C-labeled aliphatic halides were examined after formation in an in vitro microsomal system. After exhaustive solvent extraction of the precipitated microsomal protein, the AAAs were isolated by Pronase digestion, followed by filtration through a 500 mol. wt. exclusion membrane. The liberated AAAs were applied to a constant flow DC-4A cation exchange column, resolved by stepwise buffer elution, collected and counted for radioactivity. Column recovery for applied radioactivity was 100 ± 4%. Generally, 1–4 different AAAs (defined by eluting radioactivity) were resolved, with each organohalogen displaying a characteristic elution profile. Methyl iodide, trichloroethylene and 1,2-dichloroethylene had a single major AAA while bromotrichloromethane, 1,2-dibromoethane, 1,1,1-trichloroethane, 1,2-dichloroethane, 1,1,2-trichloroethane, 2-bromo-2-chloro-1,1,1-trifluoroethane, chloroform and carbon tetrachloride had up to 4 AAAs or more, indicating combinations of binding site(s) and reactive intermediate(s). The single AAA formed following incubation of methyl iodide with the microsomes was identified as S-methylcysteine. Thus, this method appears capable of resolving binding sites and is the initial isolation step for identifying specific adducts to proteins.     

The baboon model under anesthesia for in vivo cerebral blood flow studies using single photon emission computed tomographic (SPECT) techniques.

Single photon emission computed tomography of the brain can be useful in animal experimentation directed toward cerebral conditions. A well established and understood baboon model, necessarily under anesthesia, could be especially valuable in such investigations. Six normal baboons were studied under various anesthetic agents and their combinations: ketamine, thiopentone, pentobarbitone, and halothane. Cerebral blood flow (CBF) studies were performed with 99mTc-HMPAO. CBF effects from various anesthesia were detected, requiring careful choice of the anesthesia for cerebral investigations.     

α-Guanidinoglutaric Acid in Cobalt-Induced Epileptogenic Cerebral Cortex of Cats

: Guanidino compounds in the cobalt-induced epileptogenic cerebral cortex of cats were fluorometrically analysed by a JASCO G-520 guanidino compounds analyser, and an unknown high peak was observed in the chromatogram that was identical to the peak of authentic α-guanidinoglutaric acid. In another experiment, the substance was extracted from the cobalt focus tissue, converted into dimethylpyrimidyl derivative-butylester, and analysed by a GC/MS technique. The mass spectrum of the substance was identical to the dimethylpyrimidyl derivative of α-guanidinoglutaric acid butylester (M⁺= 365).     

Fragmentation pattern of permethyl 6-C-glycosylflavones in electron impact mass spectrometry

A mass spectral fragmentation pattern of permethyl 6-C-glycosylflavones is proposed from the MS data of permethyl derivatives mono-O-deuteriomethylated in the 2″-, 3″-, 4″- or 6″-positions. The synthesis of these compounds via O″-glycosyl-6-C-glucosylflavones is described.     

Structural determination of C-glycosylflavones by mass spectrometry of their permethyl ethers

Permethylated C-glycosylflavones give well defined MS, including in all cases an important molecular peak. The observed fragmentations are characteristic for the nature and position of the sugar. The 6-C and 8-C glycosylated derivatives are clearly differentiated. In dissymmetrical 6,8-di-C-glycosylflavones, the natures of the sugar in both the 6- and 8- positions can be determined. The structures of several natural compounds are discussed.