scholarly journals HIDDEN ALLELES AT THE α-GLYCEROPHOSPHATE DEHYDROGENASE LOCUS IN COLIAS BUTTERFLIES

Genetics ◽  
1976 ◽  
Vol 83 (1) ◽  
pp. 149-167
Author(s):  
George B Johnson

ABSTRACT By varying polyacrylamide gel pore size, the α-glycerophosphate dehydrogenase locus of Colias butterflies is shown to contain at least five alleles, rather than the two which had been reported previously. Two of the alleles have the same apparent net charge, and presumably are detected electrophoretically because of conformational differences. Additional variation occurs in the isoelectric points of the proteins. It is suggested that electrophoresis employing a single gel of intermediate pore size will fail to discriminate between many alleles, and that the concept of electrophoretic alleles as differing simply in charge may not always be appropriate. "How does one know what it is one believes When it's so difficult to know what it is one knows?" —Jumpers (Stoppard, 1972)

1979 ◽  
Vol 44 (6) ◽  
pp. 1828-1834
Author(s):  
Asja Šiševa ◽  
Jiřina Slaninová ◽  
Tomislav Barth ◽  
Stephan P. Ditzov ◽  
Luben M. Sirakov

Isoelectric focusing on polyacrylamide gel columns of three native crystalline commercial preparations of insulin and 125I-labelled insulin was carried out. All the compounds studied contained three components of different isoelectric points. The largest fraction, having pI 5.60 ± 0.05, was common to all preparations. The other two fractions were situated in the acid region of pH between pI 4.5 and 5.2. The presence of these fractions is explained by the contamination of crystalline insulins by proinsulin and by the formation of des-amido derivatives during the dissolving and storage of insulin samples, and, in case of labelled insulin, also by the presence of heavily iodinated insulin and contaminating components. The isoelectric focusing of the complex 125I-insulin-antibody showed a peak of radioactivity having pI 6.15 ± 0.05.


1981 ◽  
Vol 46 (3) ◽  
pp. 807-816 ◽  
Author(s):  
Věra Jonáková ◽  
Dana Čechová ◽  
Otakar Mach

Cow colostrum contains three isoinhibitors A, B, and C, which are glycoproteins. In this study isoinhibitor A was isolated and characterized and the structure of its protein moiety compared with the known protein structures of isoinhibitors B and C. It was found that the primary structure of isoinhibitor A is identical with the primary structure of isoinhibitor B except that the C-terminus of its molecule is shorter by five amino acid residues. Four discrete chromatographic forms (I-IV) with different isoelectric points (pI 3.8 - I, 4.0 - II, 4.3 - III, and 4.5 - IV) were isolated by chromatography on SE-Sephadex, Form I is identical with isoinhibitor A. Forms II, III, and IV are represented by mixtures of isoinhibitors A, B, and C with a heterogeneous carbohydrate moiety which affects the total net charge of the individual inhibitor forms.


1976 ◽  
Vol 54 (12) ◽  
pp. 1029-1033 ◽  
Author(s):  
M Saleem ◽  
Burr Atkinson

Rat liver ribosomes prepared in low salt buffer contain basic and acidic proteins not found on ribosomes washed in high salt buffer. Proteins extracted from liver ribosomes by 500 mM KCl were characterized by acid urea–polyacrylamide gel electrophoresis, sodium dodecyl sulfate – polyacrylamide gel electrophoresis and gel isoelectric focusing. The salt-solubilized proteins contain 12 polypeptides with a molecular weight over 67 000, several polypeptides with molecular weights less than 67 000, and three polypeptides whose molecular weight exceeded 130 000. Ten to 12 of the proteins were basic, and about 24 acidic proteins were partially or wholly extracted from the ribosomes. Four of the acidic proteins have isoelectric points less than 4.5.


1993 ◽  
Vol 60 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Lina Chianese ◽  
Giuseppina Garro ◽  
Francesco Addeo ◽  
Gloria Lopez-Galvez ◽  
Mercedes Ramos

SummaryA novel ovine αs2-casein variant has been detected using discontinuons polyacrylamide gel electrophoresis at alkaline pH, two dimensional electrophoresis and immunoblotting. It is characterized by a greater negative net charge and a lower isoelectric point compared with the most common ovine αs2-casein variant. The phenotypic frequency in the Manchega breed is 5·5%.


1989 ◽  
Vol 35 (5) ◽  
pp. 778-782 ◽  
Author(s):  
J T Wu ◽  
R K Pieper ◽  
L H Wu ◽  
J L Peters

Abstract We isolated myoglobin from sheep heart by homogenizing cardiac muscle in 70%-saturated ammonium sulfate, followed by chromatography on a column containing carboxymethyl(CM)-Sephadex gel. Two major isoforms of myoglobin, designated Mb 7.9 and Mb 8.1, were separated by chromatofocusing and were distinguished by their different patterns seen on either isoelectrofocusing or on electrophoresis on polyacrylamide gel. The isoelectric points of the major bands of Mb 7.9 and Mb 8.1 were 7.4 and 7.16, respectively. Both isoforms were identical in size when examined by gel filtration chromatography but differed slightly when analyzed by polyacrylamide gradient gel in the presence of sodium dodecyl sulfate. The Mr of Mb 7.9 (15,900 Da) is slightly smaller than that of Mb 8.1 (18,400 Da). When reacted against rabbit anti-sheep myoglobin, two isoforms also appeared as two nonidentical precipitin lines on agarose gel.


1980 ◽  
Vol 59 (s6) ◽  
pp. 21s-24s ◽  
Author(s):  
Kazuo Murakami ◽  
Saori Takahashi ◽  
Shigehisa Hirose ◽  
Yukio Takii ◽  
Tadashi Inagami

1. A completely inactive renin was isolated from hog kidney extract by affinity chromatography on pepstatin-aminohexyl-Sepharose and on an Affi-Gel Blue column. 2. This inactive renin had a molecular weight of 43 000 ± 1500 as determined by gel filtration on Ultrogel AcA 44. Upon activation with trypsin, its molecular weight fell to 41 000 ± 1400. 3. The inactive renin lacked the ability to bind renin-binding substance whereas trypsin-activated renin was able to bind the renin-binding protein and to form high-molecular-weight renin. 4. Chymotrypsin as well as trypsin could activate the inactive renin although less effectively. 5. The active renins generated from the inactive renin by the action of different proteolytic enzymes differed in their net charge, reflecting the specificities of the proteases used; the isoelectric points of the native, the trypsin-activated and the chymotrypsin-activated forms of renin occurred at pH 5.3, 5.1 and 4.8 respectively.


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