Linkage of loci encoding a kidney endothelial antigen and fumarate hydratase (Fh-1) in the rat

In the rat a single locus, provisionally designated Eag-1, controls the expression of an antigen present on the endothelium of kidney peritubular capillaries and veins. We have examined the linkage relationship between Eag-1 and 10 polymorphic loci including hemoglobin b, fumarate hydratase, peptidase-3, urinary pepsinogen, seminal vesicle protein, glycerophosphate dehydrogenase, esterase-1, esterase-6, pinkeye, and hooded. Tissue samples from animals derived from (AUG X BN.1C)F1 X AUG and (AUG X BN.1C)F1 X BN.1C backcrosses were examined and a linkage association between Eag-1 and Fh-1 (EC 4.2.2.1) was detected. The linkage distance between Eag-1 and Fh-1 is 21 cM (chi 2 = 27.9; p = 0.00001) and this association defines the third locus in the tenth (X) linkage group of the rat.     

ProAlanase is an Effective Alternative to Trypsin for Proteomics Applications and Disulfide Bond Mapping

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Highlights

• •ProAlanase is a powerful protease for efficient low pH disulfide bond mapping.
• •High suitability for analysis of histone family members and their PTMs.
• •Accurate phosphorylation profiling in proline-rich proteins.
• •Sequence coverage increase and full de novo sequencing in combination with trypsin.

     

Reaction of tRNAPhe from yeast with 1-fluoro-2,4-dinitrobenzene. Attachment sites of the potential antigenic-determining 2,4-dinitrophenyl residues.

The reaction of 1-fluoro-2,4-dinitrobenzene with tRNAPhe from yeast, for the introduction of antigenic-determining 2,4-dinitrophenyl residues into tRNA, took place only at adenosine residues in tRNAPhe. After reaction at pH 8.0 and 50 degrees C two kinds of products were detected: one was ribose-modified adenosine which was derived from the 3' terminus of tRNA, and the other was base-modified adenosine. The sites and extent of the modification of each particular adenosine residue of tRNAPhe were determined as follows: 5 (6% modified), 31 (2%), 35 (36%), 67 (5%), and 76 (51%). Thus mainly the terminal adenosine and one adenosine in the anticodon loop bear the 2,4-dinitrophenyl residue.     

The effect of sea shore displacement on population age structure of coastal Alnus glutinosa (L.) Gaertn.

The age structure of Alnus glutinosa (L.) Gaertn. populations was studied in two areas on the coast of the Baltic Sea. One area, situated in Upplatid, eastern central Sweden, at 60°07'N, has a relative land uplift of 5.3 mm yr⁻¹; the other area, situated in Blekinge, southeastern Sweden, at 56°10'N, is nearly stable. The spatial distribution of 200 Alnus individuals of various age classes at nine sites was analyzed in order to reconstruct establishment history. In the land uplift area, the youngest individuals were found in the lowest parts of the sites, and age and elevation were significantly correlated. In the area without land uplift, no such pattern was found. Regression analysis of the time/space pattern of establishment in the land uplift area showed that the zone where individuals establish follows the moving shore line with roughly constant speed. Alnus glutinosa uses two different regenerative strategies: (1) continuous colonization of emerging land from seeds (with subsequent mortality of the older trees) in the land uplift area, and (2) regeneration from old stem bases, forming multistemmed trees, in the area without land uplift.     

Tyroslyl-tRNA synthetase from baker's yeast. Rapid isolation by affinity elution, molecular weight of the enzyme, and determination of essential sulfhydryl groups.

Tyrosyl-tRNA synthetase (EC 6.1.1.1) has been isolated from baker's yeast with an overall purification factor of more than 5000. After opening the cells, pH 4.8 precipitation, ammonium sulfate fractionation, removal of the nucleic acids with DEAE-cellulose and chromatography on CM-Sephadex, the critical purification step is the elution of the cation-exchanger-bound tyrosyl-tRNA synthetase with tRNATyr. The homogeneous enzyme exhibits a molecular weight of 40 000 as estimated by sedimentation equilibrium centrifugation and dodecylsulfate-gel electrophoresis under reducing and non-reducing conditions. Gel filtration experiments show a molecular weight of about 100 000 indicating the existence of an active dimeric form. The possibility of proteolytic cleavage of the enzyme is excluded. The reaction of tyrosyl-tRNA synthetase with p-chloromercuribenzoate and N-ethylmaleimide reveals two repidly reacting sulfhydryl groups per subunit of molecular weight 40 000, as demonstrated by the inhibition of aminoacylation and the isolation of enzyme-inhibitor complexes. In addition an efficient purification method is described for isolating tRNATyr from soluble ribonucleic acid from baker's yeast in three chromatographic steps in a yield of 28%.     

Inhibition of chemical oxidation and reduction of cytochromes ƒ and b-559 by carbonylcyanide p-trifluoromethoxy phenylhydrazone

The presence of low (1–4 μM) concentrations of carbonylcyanide p-trifluoromethoxyphenylhydrazone during actinic illumination of chloroplasts generally inhibits the rate of subsequent dark chemical oxidation-reduction reactions of cytochrome ƒ and b-559. Ferricyanide oxidation and ascorbate reduction of cytochromes ƒ and b-559 are inhibited, as is hydroquinone reduction of cytochrome b-559. Inhibition by carbonylcyanide p-trifluoromethoxyphenylhydrazone of hydroquinone reduction of cytochrome ƒ, the most rapid of these chemical oxidation-reduction reactions, cannot be detected. The rate of the chemical redox reactions of the cytochromes in the presence of carbonylcyanide p-trifluoromethoxyphenylhydrazone are all markedly dependent upon the concentration of oxidant or reductant except the hydroquinone reduction of cytochrome b-559 photooxidized in the presence of carbonylcyanide p-trifluoromethoxyphenylhydrazone.

The data is interpreted in terms of an effect of carbonylcyanide p-trifluoromethoxyphenylhydrazone on thylakoid membrane structure which generally inhibits accessibility to the hydrophobic interior of the membrane, possibly through an increase in membrane microviscosity. The question of whether such an effect on membrane structure could be involved in uncoupling or inhibition effects of the carbonylcyanidephenylhydrazone compounds is discussed, as is the special effect of these compounds on the cytochrome b-559 photoreactions at room temperature.