scholarly journals Paramyosin in invertebrate muscles. II. Content in relation to structure and function.

1976 ◽  
Vol 71 (1) ◽  
pp. 273-279 ◽  
Author(s):  
R J Levine ◽  
M Elfvin ◽  
M M Dewey ◽  
B Walcott
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Thick Filament ◽  
Structure And Function ◽  
Active Tension ◽  
Tension Development ◽  
Force Development ◽  
And Function

By quantitative sodium dodecyl sulfate-polyacrylamide gel electrophoresis, paramyosin:myosin heavy chain molecular ratios were calculated for three molluscan muscles:Aequipecten striated adductor, Mercenaria opaque adductor, and Mytilus anterior byssus retractor; and four arthropodan muscles:Limulus telson, Homarus slow claw. Balanus scutal depressor, and Lethocerus air tube retractor. These ratios correlate positively with both thick filament dimensions and maximum active tension development in these tissues. The role of paramyosin in these muscles is discussed with respect to the following characteristics: force development, "catch," and extreme reversible changes in length.

scholarly journals Accelerated hepatic haem catabolism in the selenium-deficient rat

1977 ◽  
Vol 168 (1) ◽  
pp. 105-111 ◽  
Author(s):  
R F Burk ◽  
M A Correia
Keyword(s):  
Urinary Excretion ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Fold Increase ◽  
Microsomal Cytochrome ◽  
Haem Oxygenase ◽  
Cytochrome P 450

1. Hepatic microsomal cytochrome P-450 concentrations are lower in selenium-deficient rats treated with phenobarbital for 4 days than in similarly treated control rats. 2. No defect in haem synthesis was found on the basis of measurements of delta-aminolaevulinate synthase (EC 2.3.1.37), delta-aminolaevulinate dehydratase (EC 4.2.1.24) and ferrochelatase (EC 4.99.1.1) activities, and urinary excretion of delta-aminolaevulinate, porphobilinogen, uroporphyrin and coproporphyrin. 3. No defect in apo-(cytochrome P-450) separated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 4. An increase in haem catabolism was found. An 8-fold increase in hepatic microsomal haem oxygenase (EC 1.14.99.3) activity occurred in selenium-deficient rats after phenobarbital treatment, compared with a less than 2-fold increase in control rats. Also excretion of 14CO in the breath after administration of delta-amino[5-14C]laevulinate was greater by phenobarbital-treated selenium-deficient rats than by similarly treated controls. 5. These studies demonstrate that the defective induction of cytochrome P-450 by phenobarbital in selenium-deficient rats is accompanied by increased haem catabolism. This could be due to increased breakdown of cytochrome P-450 or to catabolism of haem before it attaches to the apo-cytochrome. The role of selenium in stabilizing cytochrome P-450 and/or in protecting haem from breakdown remains to be determined.

Observations on the structure and function of the haemoglobin from the cuticle of Nippostrongylus brasiliensis (Nematoda)

Parasitology ◽  
1981 ◽  
Vol 83 (2) ◽  
pp. 411-424 ◽  
Author(s):  
M. J. Sharpe ◽  
D. L. Lee
Keyword(s):  
Molecular Weight ◽  
Optical Density ◽  
Small Area ◽  
Fluid Layer ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Structure And Function ◽  
Nippostrongylus Brasiliensis ◽  
And Function ◽  
Absorbance Spectra

SUMMARYThe fluid layer within the cuticle of the nematode Nippostrongylus brasiliensis contains haemoglobin. The absorbance spectra of the haemoglobins extracted from whole nematodes were measured spectrophoto-metrically and the spectra of cuticular haemoglobin in individual living nematodes was obtained by microdensitometry. Adult female nematodes were confined under cover-slips in oxygenated saline and measurements of optical density of a small area of the cuticular haemoglobin were taken at 10 sec intervals. The optical density decreased over a period of 4 min at 543 nm and increased at 553 nm indicating deoxygenation of the cuticular haemoglobin; irrigation with fresh saline restored the haemoglobin to its oxygenated state. This demonstrates that cuticular haemoglobin loads and unloads oxygen in the living animal. Isoelectric focusing showed that mature nematodes have haemoglobins which are isoelectric around pH 7·0 and at pH 9·8. Isolated cuticular fluid contained the haemoglobin which was isoelectric at pH 9·8, but no other haemoglobin, and immature adults, which do not have cuticular haemoglobin, contained only those haemoglobins which were isoelectric at pH 7·0. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and column chromatography showed that the molecular weight of the cuticular haemoglobin sub-unit is 16·9–17·5 × 103 Daltons and that the haemoglobin exists primarily as a tetrameric molecule with a molecular weight of 65–75 × 103 Daltons. The presence of cuticular haemoglobin may allow adult Nippostrongylus to exploit oxygen-deficient areas within the environment of the rat's intestine where it would otherwise be unable to survive for prolonged periods.

scholarly journals STUDIES ON NUCLEAR STRUCTURE AND FUNCTION IN TETRAHYMENA PYRIFORMIS

1970 ◽  
Vol 47 (3) ◽  
pp. 631-636 ◽  
Author(s):  
Martin A. Gorovsky
Keyword(s):  
Nuclear Structure ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Tetrahymena Pyriformis ◽  
Structure And Function ◽  
Polyacrylamide Gel ◽  
And Function

Histones were extracted from isolated macro- and micronuclear fractions and from nucleohistone fibers which were prepared from the isolated macronuclear fraction. Analysis of these histones by polyacrylamide gel electrophoresis indicated that there are electrophoretic differences between the histones of macro- and micronuclei.

scholarly journals Effects of partial extraction of troponin complex upon the tension-pCa relation in rabbit skeletal muscle. Further evidence that tension development involves cooperative effects within the thin filament.

1986 ◽  
Vol 87 (5) ◽  
pp. 761-774 ◽  
Author(s):  
R L Moss ◽  
J D Allen ◽  
M L Greaser
Keyword(s):  
Functional Groups ◽  
Thin Filament ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Isometric Tension ◽  
Original Position ◽  
Active Tension ◽  
Tension Development ◽  
Psoas Muscles ◽  
Partial Extraction

Partial extraction of troponin C (TnC) decreases the Ca2+ sensitivity of tension development in mammalian skinned muscle fibers (Moss, R. L., G. G. Giulian, and M. L. Greaser. 1985. Journal of General Physiology. 86:585), which suggests that Ca2+-activated tension development involves molecular cooperativity within the thin filament. This idea has been investigated further in the present study, in which Ca2+-insensitive activation of skinned fibers from rabbit psoas muscles was achieved by removing a small proportion of total troponin (Tn) complexes. Ca2+-activated isometric tension was measured at pCa values (i.e., -log[Ca2+]) between 6.7 and 4.5: (a) in control fiber segments, (b) in the same fibers after partial removal of Tn, and (c) after recombination of Tn. Tn removal was accomplished using contaminant protease activity found in preparations of LC2 from rabbit soleus muscle, and was quantitated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and scanning densitometry. Partial Tn removal resulted in the development of a Ca2+-insensitive active tension, which varied in amount depending on the duration of the extraction, and concomitant decreases in maximal Ca2+-activated tensions. In addition, the tension-pCa relation was shifted to higher pCa values by as much as 0.3 pCa unit after Tn extraction. Readdition of Tn to the fiber segments resulted in the reduction of tension in the relaxing solution to control values and in the return of the tension-pCa relation to its original position. Thus, continuous Ca2+-insensitive activation of randomly spaced functional groups increased the Ca2+ sensitivity of tension development in the remaining functional groups along the thin filament. In addition, the variation in Ca2+-insensitive active tension as a function of Tn content after extraction suggests that only one-third to one-half of the functional groups within a thin filament need to be activated for complete disinhibition of that filament to be achieved.

scholarly journals Structural and Functional Importance of Transmembrane Domain 3 (TM3) in the Aspartate:Alanine Antiporter AspT: Topology and Function of the Residues of TM3 and Oligomerization of AspT

2009 ◽  
Vol 191 (7) ◽  
pp. 2122-2132 ◽  
Author(s):  
Kei Nanatani ◽  
Peter C. Maloney ◽  
Keietsu Abe
Keyword(s):  
Transmembrane Domain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Hydrophobic Core ◽  
Amino Acid Residues ◽  
Cysteine Scanning Mutagenesis ◽  
Domain 3 ◽  
Hydrophilic Residues ◽  
And Function

ABSTRACT AspT, the aspartate:alanine antiporter of Tetragenococcus halophilus, a membrane protein of 543 amino acids with 10 putative transmembrane (TM) helices, is the prototype of the aspartate:alanine exchanger (AAE) family of transporters. Because TM3 (isoleucine 64 to methionine 85) has many amino acid residues that are conserved among members of the AAE family and because TM3 contains two charged residues and four polar residues, it is thought to be located near (or to form part of) the substrate translocation pathway that includes the binding site for the substrates. To elucidate the role of TM3 in the transport process, we carried out cysteine-scanning mutagenesis. The substitutions of tyrosine 75 and serine 84 had the strongest inhibitory effects on transport (initial rates of l-aspartate transport were below 15% of the rate for cysteine-less AspT). Considerable but less-marked effects were observed upon the replacement of methionine 70, phenylalanine 71, glycine 74, arginine 76, serine 83, and methionine 85 (initial rates between 15% and 30% of the rate for cysteine-less AspT). Introduced cysteine residues at the cytoplasmic half of TM3 could be labeled with Oregon green maleimide (OGM), whereas cysteines close to the periplasmic half (residues 64 to 75) were not labeled. These results suggest that TM3 has a hydrophobic core on the periplasmic half and that hydrophilic residues on the cytoplasmic half of TM3 participate in the formation of an aqueous cavity in membranes. Furthermore, the presence of l-aspartate protected the cysteine introduced at glycine 62 against a reaction with OGM. In contrast, l-aspartate stimulated the reactivity of the cysteine introduced at proline 79 with OGM. These results demonstrate that TM3 undergoes l-aspartate-induced conformational alterations. In addition, nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses and a glutaraldehyde cross-linking assay suggest that functional AspT forms homo-oligomers as a functional unit.

scholarly journals Role of Surface Proteins in Vibrio cholerae Attachment to Chitin

1999 ◽  
Vol 65 (3) ◽  
pp. 1348-1351 ◽  
Author(s):  
Renato Tarsi ◽  
Carla Pruzzo
Keyword(s):  
Vibrio Cholerae ◽  
Gel Electrophoresis ◽  
Wheat Germ ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Surface Proteins ◽  
Molecular Sizes ◽  
Pronase E

ABSTRACT The role of surface proteins in Vibrio choleraeattachment to chitin particles in vitro was studied. Treatment ofV. cholerae O1 ATCC 14034 and ATCC 14035 with pronase E reduced the attachment of bacteria to chitin particles by 57 to 77%. A statistically significant reduction was also observed when the attachment to chitin was evaluated in the presence of homologous Sarkosyl-insoluble membrane proteins (MPs) (67 to 84%),N-acetylglucosamine (GlcNAc) (62%), the sugar that makes up chitin, and wheat germ agglutinin (40 to 56%), a lectin that binds GlcNAc. The soluble oligomersN,N′-diacetylchitobiose orN,N′,N"-triacetylchitotriose caused an inhibition of 14 to 23%. Sarkosyl-insoluble MPs able to bind chitin particles were isolated and visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; two of these peptides (molecular sizes, 36 and 53 kDa) specifically bind GlcNAc.

Heterozygous Abnormal Fibrinogen Osaka III with the Replacement of γ Arginine-275 by Histidine Has an Apparently Higher Molecular Weight γ-Chain Variant

1992 ◽  
Vol 68 (05) ◽  
pp. 534-538 ◽  
Author(s):  
Nobuhiko Yoshida ◽  
Shingi Imaoka ◽  
Hajime Hirata ◽  
Michio Matsuda ◽  
Shinji Asakura
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Tetraacetic Acid ◽  
Fibrin Monomer ◽  
Sds Page ◽  
Thrombotic Tendency ◽  
Chain Variant

SummaryCongenitally abnormal fibrinogen Osaka III with the replacement of γ Arg-275 by His was found in a 38-year-old female with no bleeding or thrombotic tendency. Release of fibrinopeptide(s) by thrombin or reptilase was normal, but her thrombin or reptilase time in the absence of calcium was markedly prolonged and the polymerization of preformed fibrin monomer which was prepared by the treatment of fibrinogen with thrombin or reptilase was also markedly defective. Propositus' fibrinogen had normal crosslinking abilities of α- and γ-chains. Analysis of fibrinogen chains on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the system of Laemmli only revealed the presence of abnormal γ-chain with an apparently higher molecular weight, the presence of which was more clearly detected with SDS-PAGE of fibrin monomer obtained by thrombin treatment. Purified fragment D1 of fibrinogen Osaka III also seemed to contain an apparently higher molecular weight fragment D1 γ remnant on Laemmli gels, which was digested faster than the normal control by plasmin in the presence of [ethy-lenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA).

Low Molecular Weight Trypsin-Plasmin Inhibitors Isolated from Papain Treated Urinary Trypsin Inhibitor

1982 ◽  
Vol 47 (01) ◽  
pp. 014-018 ◽  
Author(s):  
H Sumi ◽  
N Toki ◽  
S Takasugi ◽  
S Maehara ◽  
M Maruyama ◽  
...  
Keyword(s):  
Trypsin Inhibitor ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Chromatography ◽  
Urinary Trypsin Inhibitor ◽  
Plasmin Activity ◽  
Molecular Weights ◽  
Plasmin Inhibitors

SummaryPapain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.

Identifikasi Daging Tikus Pada Produk Baso Dengan Metode Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE)

2018 ◽  
Vol 26 (2) ◽  
pp. 058
Author(s):  
Anna P. Roswiem ◽  
Triayu Septiani
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Sds Page

<em>Bahan<strong> </strong>baku untuk membuat baso adalah daging hewan, pada umumnya dari daging sapi, ayam, ikan dan babi. Di beberapa daerah di Indonesia terjadi kasus baso tikus. Tujuan penelitian ini adalah menguji ada tidaknya kandungan daging tikus pada produk baso yang dijual di pasar Cempaka Putih-Kecamatan Kramat Jakarta Pusat dan di pedagang baso atau mie baso di sekitar kampus Universitas YARSI Jakarta. Daging adalah protein salah satu metode untuk mengidentifikasi protein adalah metode Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE).<strong> </strong>Hasil penelitian menunjukkan bahwa dari 6 sampel baso terindikasi ada 2 sampel baso dengan nomor 1 dan 5 yang dibuat dari campuran daging sapi dan tikus; ada 1 sampel baso dengan nomor 6 yang terbuat dari daging tikus; dan 2 sampel baso dengan nomor 2 dan 3 yang terbuat dari campuran sapi  dan babi, dan hanya 1 sampel baso dengan nomor sampel 4 yang benar-benar terbuat dari daging sapi.</em>

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