Identical Electrophoretic Mobility Research Articles

21 A Genetic Variant of Human Mitochondrial Malate Dehydrogenase

The enzyme malate dehydrogenase (MDH) is known to exist in two distinct forms in most mammalian tissues. One is present in the cytoplasm as a soluble enzyme (S-MDH), and the other is bound to the mitochondria (M-MDH). Among the distinct physical and chemical properties of these two enzymes are the different patterns seen after starch gel electrophoresis and specific enzymatic staining (see diagram: usual). Recent studies have suggested that the usual minor mitochondrial bands (1–4) are conformational modifications of a single protein, band 5. We have previously reported a rare genetic variant of soluble MDH found in the red cells of one apparently normal Negro female out of 3000 individuals examined. This report concerns a new inherited electrophoretic variant of M-MDH found in either leukocyte or placental extract of 3 of 350 unselected normal individuals. The electrophoretic pattern of this variant is shown in the diagram. The two additional major bands of MDH activity have identical electrophoretic mobility with minor bands 4 and 3 of the normal mitochondrial pattern. Family studies of two of the probands show that affected individuals are heterozygous for a relatively common autosomal mutant gene. All of the individuals found to have the mitochondrial variant have normal S-MDH patterns, adding further evidence that the two intracellular forms of MDH are under the control of different genes. (SPR)

Haemoglobin J-Bangkok: a clinical, haematological and genetical study.

SUMMARYA Thai family with haemoglobins A + J‐Bangkok in nine persons is described. This rare abnormal pigment had identical electrophoretic mobility to other haemoglobins J, but, as α2β256Asp, is not similar to any previously described haemoglobin. Carriers of this haemoglobin were clinically and haematologically normal except for the presence of 47.4–67.2 per cent Hb J. It was also possible to follow the increment of Hb J‐Bangkok from 16.15 per cent in the cord blood to 46 per cent at 2½ months and to 55.18 per cent at 1 year of age. One person is believed to harbour both an α‐thalassaemia and Hb J‐Bangkok genes without evidence of interaction.

THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: VI. GLUCANS FROM TRICHOPHYTON GRANULOSUM, TRICHOPHYTON INTERDIGITALE, MICROSPORUM QUINCKEANUM, TRICHOPHYTON RUBRUM, AND TRICHOPHYTON SCHÖNLEINII

Polysaccharides obtained from each of the organisms designated in the title have been resolved into three groups: galactomannans I, galactomannans II, and glucans. The five glucans were homogeneous under conditions of electrophoresis, and had identical electrophoretic mobilities and infrared spectra. Methylation and hydrolysis of the glucans yielded varying amounts of the following: 2,3,4,6-tetra-O-methyl-D-glucose, 2,3,4-tri-O-methyl-D-glucose, 2,4,6-tri-O-methyl-D-glucose, and 2,4-di-O-methyl-D-glucose. The glucans were therefore branched polysaccharides, with branches formed by substitution at the C-3 and C-6 positions of D-glucopyranose units and terminated by D-glucopyranose units. The linear portions of the glucans contained 1 → 6 and 1 → 3 linkages but in varying amounts. These differences and some variation in the degrees of branching constituted the only dissimilarities detectable in the glucans by these structural studies.

Characterization of Pituitary and Peptide Hormones by Electrophoresis in Starch Gel

SUMMARY A variety of pituitary and other protein hormone preparations exhibited characteristic patterns in starch gel electrophoresis, with the Ferguson and Wallace modification of Poulik’s discon- tinuous buffer system. Five human growth hormone prepara- tions prepared by different methods appeared similar. The four major bands in human growth hormone were inseparable from the four major bands in three different ovine prolactin preparations. Human prolactin shared two major bands in common with both human growth hormone and ovine prolactin. Human, simian, and porcine growth hormone shared three major bands in common, indistinguishable from one another, even with change in pH and prolonged electrophoresis. The simian prepa- ration had one and the porcine preparation four major compo- nents not detected in the human preparation. Purified bovine growth hormone had no bands in common with the other three preparations. Among the melanocyte-stimulating hormones (MSH) , syn- thetic (r-MSH (Hofmann) had the identical electrophoretic mobility as the major component in Schally’s preparation. The characteristic pattern of corticotropin A1 and AQ and ar-MSH and /I-MSH was established; a variety of corticotropin prepara- tions were examined, and the content of each of these peptides was assessed. Three purified parathyroid hormone preparations and two purified relaxin preparations were found not to be homogeneous

Variations in the Lactic Dehydrogenase of Vertebrate Erythrocytes

Erythrocytes from representatives of the 5 classes of vertebrates revealed a marked species variation in the number of LDH isozymes, in the distribution of the total LDH activity among these isozymes, and in their electrophoretic mobilities. Starch gel electrophoresis of hemolysates followed by direct histochemical demonstration of LDH activity with nitro blue tetrazolium as dye and phenazine methosulfate as electron transporter showed that closely related species exhibited similar LDH patterns. The rhesus monkey had LDH isozymes of similar pattern to those of human hemolysate but slightly slower in electrophoretic mobility. The goat and sheep each had 1 band of LDH activity in their erythrocytes of identical electrophoretic mobility, whereas the single band in steer hemolysate migrated slightly faster. The 5 bands of chicken hemolysate were quite similar in pattern to the 5 bands of duck hemolysate but migrated slightly faster and exhibited a different distribution of the total LDH activity. The 2 species of snake each had 1 band of LDH activity with identical mobility. Staining occurred with the levorotatory form of the substrate and not with the dextrorotatory form. Examination of more than 380 human hemolysates failed to reveal any differences among individuals in the main LDH bands. The genetic basis for the species differences in erythrocyte lactic dehydrogenases is discussed.

Continuous antidromic electrophoresis

An instrument is described for the continuous separation of substances with similar but not identical electrophoretic mobilities. The supporting medium (paper or plastic film supported gel) is moved continuously, mechanically, in a direction opposite to the migration of the ions. In this manner, the electrophoresis may be continued for long periods of time keeping the ions in the electrical field. Contact is made by rollers dipped into a suitable buffer. The application of the instrument to amino acids is described. Cooling is effected by passing the strip through an inert liquid (e.g., carbon tetrachloride) which is cooled by a coil through which a cooling fluid moves. The eighteen most common amino acids were readily separated. For example, leucine, isoleucine, and valine are widely separated.

A study of rhodium(III) oxalates by paper electrophoresis, paper chromatography, ion-exchange chromatography and spectrophotometry

The results obtained in an investigation of rhodium(III) oxalates indicate that heating of pure rhodium(III) hydroxide with oxalic acid solution produces RhOx 3 −3 to a great extent, but that the reaction does not go to completion, other aquo-coördinated oxalato complexes of rhodium being formed in smaller quantities. Evidence is presented that in order to obtain complete conversion of rhodium(III) into potassium rhodiotrioxalate the chloride must be heated under reflux with four to five times its weight of potassium oxalate for at least 6 hours. The absorption spectrum, the stability to heating and aging at room temperature in solution, as well as the electrophoretic, paper- and ion-exchange chromatographic properties of the rhodiotrioxalate ion were studied. It was shown that the dextro- and laevo-forms of RhOx 3 −3 have identical electrophoretic mobilities.

The electrophoretic mobilites of adapted MEF 1 poliomyelitis virus and its soluble antigen

Electrophoretic studies on emulsions of MEF 1 virus-infected sucking mouse brain, indicate that the three components which can be detected by physico-chemical and biological means, namely, the soluble antigens, as well as the 24 mω and the 29 mω infective particles have identical electrophoretic mobilities at pH 8.2. This finding may be of significance in determining whether soluble antigen forms an integral part of the MEF 1 virus particle or not. Furthermore the material that has been employed in which “soluble antigen” and virus are not as vastly different in dimensions as is the case with larger viruses, may be particularly useful in the elucidation of problems concened with the formation and structure of viruses.