scholarly journals Studies on synthesis and degradation rates and some molecular properties of guinea-pig muscle acylphosphatase

1984 ◽  
Vol 217 (2) ◽  
pp. 499-505 ◽  
Author(s):  
G Liguri ◽  
P Nassi ◽  
G Camici ◽  
G Manao ◽  
G Cappugi ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Group Analysis ◽  
Exchange Chromatography ◽  
Molecular Forms ◽  
Stoichiometric Ratio ◽  
Main Form ◽  
Purification Technique ◽  
Degradation Rates ◽  
Pig Muscle ◽  
Synthesis And Degradation

Acylphosphatase (acylphosphate phosphohydrolase, EC 3.6.1.7) was purified from guinea-pig muscle by a procedure involving immuno-affinity chromatography and a subsequent ion-exchange chromatography. This purification technique gave an overall yield of about 60% and permitted the isolation of three molecular forms with acylphosphatase activity, with a distribution greatly resembling those found in horse and turkey muscle. The main form appears to be very similar to the corresponding form in horse and turkey muscle, as indicated by amino acid composition, end-group analysis, the presence of glutathione as a mixed disulphide in almost the same stoichiometric ratio and kinetic analysis. From turnover data, the main form of acylphosphatase in guinea-pig muscle exhibits a degradation constant of 0.10 day-1, corresponding to a half-life of 6.8 days. These values are very close to those found for muscle total soluble proteins.

Preparation and properties of three analogues of [5-leucine]enkephalin, substrates for enzyme conversion studies

1985 ◽  
Vol 50 (6) ◽  
pp. 1329-1334
Author(s):  
Jaroslav Vičar ◽  
Linda Servítová ◽  
Martin Flegel ◽  
Karel Hauzer ◽  
Tomislav Barth
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Guinea Pig ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Guinea Pig Ileum ◽  
Opioid Activity ◽  
C Terminus ◽  
N Terminus ◽  
Fragment Condensation

Analogues of [5-Leu]enkephalin, prolonged by methionine on the N-terminus or, by lysine or methionine on the C-terminus were prepared by fragment condensation, purified by ion exchange chromatography or high-pressure liquid chromatography. The substances were characterised by their opioid activity in a test on guinea-pig ileum in comparison with the activity of [5-Leu]enkephalin.

scholarly journals Synthesis and degradation rates of collagens in vivo in whole skin of rats, studied with 18O2 labelling

1986 ◽  
Vol 240 (2) ◽  
pp. 431-435 ◽  
Author(s):  
J A Molnar ◽  
N Alpert ◽  
J F Burke ◽  
V R Young
Keyword(s):  
Gas Chromatography Mass Spectrometry ◽  
Collagen Turnover ◽  
Growing Rats ◽  
Soluble Collagen ◽  
Insoluble Collagen ◽  
Degradation Rates ◽  
Labelling Procedure ◽  
Skin Biopsies ◽  
Synthesis And Degradation

Rats of synthesis and degradation in vivo of collagens in 0.5 M-acetic acid-soluble and -insoluble extracts from skins of three growing rats were determined by using a labelling procedure involving exposure of the animals to an atmosphere of 18O2 for 36 h. For comparison, rats also received injections of [2H]proline. Serial skin biopsies were taken at frequent intervals over 392 days. Enrichment of 18O and 2H in the hydroxyproline of the collagen fractions was determined by gas chromatography-mass spectrometry. Changes in size of the soluble and insoluble collagen pools were considered in the evaluation of isotope kinetic data. The insoluble collagen fraction showed no degradation. The efflux (mean +/- S.D., expressed as mumol of hydroxyproline) from the soluble collagen pool was estimated to be 59.9 +/- 1.9 per day from the 18O data, and 25.5 +/- 7.5 per day from the 2H results. The finding indicates significant reutilization of 2H-radiolabelled proline for hydroxyproline synthesis. From these isotope data and estimates of size of the collagen pools it was determined that 55% of the collagen disappearing from the soluble pool was due to maturation into insoluble collagens and 45% of the disappearance was a result of actual degradation of soluble collagen. These results confirm the utility of 18O2 as a non-reutilizable label for studies of collagen turnover in vivo.

Adenosine triphosphate concentration in guinea pig muscle after denervation

1957 ◽  
Vol 13 (3) ◽  
pp. 117-118 ◽  
Author(s):  
L. Michelazzi ◽  
M. A. Mor ◽  
M. U. Dianzani
Keyword(s):  
Guinea Pig ◽  
Adenosine Triphosphate ◽  
Pig Muscle

Kinetic analysis of segmentation gene interactions in Drosophila embryos

Development ◽  
1999 ◽  
Vol 126 (7) ◽  
pp. 1515-1526 ◽  
Author(s):  
A. Nasiadka ◽  
H.M. Krause
Keyword(s):  
Target Genes ◽  
Vast Number ◽  
Rate Limiting Step ◽  
Degradation Rates ◽  
Time Required ◽  
Potential Interactions ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Synthesis And Degradation ◽  
Drosophila Embryos

A major challenge for developmental biologists in coming years will be to place the vast number of newly identified genes into precisely ordered genetic and molecular pathways. This will require efficient methods to determine which genes interact directly and indirectly. One of the most comprehensive pathways currently under study is the genetic hierarchy that controls Drosophila segmentation. Yet, many of the potential interactions within this pathway remain untested or unverified. Here, we look at one of the best-characterized components of this pathway, the homeodomain-containing transcription factor Fushi tarazu (Ftz), and analyze the response kinetics of known and putative target genes. This is achieved by providing a brief pulse of Ftz expression and measuring the time required for genes to respond. The time required for Ftz to bind and regulate its own enhancer, a well-documented interaction, is used as a standard for other direct interactions. Surprisingly, we find that both positively and negatively regulated target genes respond to Ftz with the same kinetics as autoregulation. The rate-limiting step between successive interactions (<10 minutes) is the time required for regulatory proteins to either enter or be cleared from the nucleus, indicating that protein synthesis and degradation rates are closely matched for all of the proteins studied. The matching of these two processes is likely important for the rapid and synchronous progression from one class of segmentation genes to the next. In total, 11 putative Ftz target genes are analyzed, and the data provide a substantially revised view of Ftz roles and activities within the segmentation hierarchy.

Differential recovery of acetylcholinesterase in guinea pig muscle and brain regions after soman treatment

1998 ◽  
Vol 17 (3) ◽  
pp. 157-162 ◽  
Author(s):  
Maxine C Lintern ◽  
Janet R Wetherell ◽  
Margaret E Smith
Keyword(s):  
Enzyme Activity ◽  
Time Course ◽  
Brain Regions ◽  
Similar Rate ◽  
Molecular Forms ◽  
Similar Degree ◽  
Brain Areas ◽  
Pig Muscle ◽  
Rate Of Recovery ◽  
The Brain

1 In brain areas of untreated guinea-pigs the highest activity of acetylcholinesterase was seen in the striatum and cerebellum, followed by the midbrain, medulla-pons and cortex, and the lowest in the hippocampus. The activity in diaphragm was sevenfold lower than in the hippocampus. 2 At 1 h after soman (27 mg/kg) administration the activity of the enzyme was dramatically reduced in all tissues studied. In muscle the three major molecular forms (A12, G4 and G1) showed a similar degree of inhibition and a similar rate of recovery and the activity had returned to normal by 7 days. 3 In the brain soman inhibited the G4 form more than the G1 form. The hippocampus, cortex and midbrain showed the greatest reductions in enzyme activity. At 7 days the activity in the cortex, medulla pons and striatum had recovered but in the hippocampus, midbrain and cerebellum it was still inhibited. 4 Thus the effects of soman administration varied in severity and time course in the different tissues studied. However the enzyme activity was still reduced in all tissues at 24 h when the overt signs of poisoning had disappeared.

scholarly journals Separation and partial characterization of guinea-pig caseins

1978 ◽  
Vol 173 (2) ◽  
pp. 633-641 ◽  
Author(s):  
R K Craig ◽  
D McIlreavy ◽  
R L Hall
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Guinea Pig ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Exchange Chromatography

1. Guinea-pig caseins A, B and C were purified free of each other by a combination of ion-exchange chromatography and gel filtration. 2. Determination of the amino acid composition showed all three caseins to contain a high proportion of proline and glutamic acid, but no cysteine. This apart, the amino acid composition of the three caseins was markedly different, though calculated divergence values suggest that some homology may exist between caseins A and B. Molecular-weight estimates based on amino acid composition were in good agreement with those based on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 3. N-Terminal analysis showed lysine, methionine and lysine to be the N-terminal residues of caseins A, B and C respectively. 4. Two-dimensional separation of tryptic digests revealed a distinctive pattern for each casein. 5. All caseins were shown to be phosphoproteins. The casein C preparation also contained significant amounts of sialic acid, neutral and amino sugars. 6. The results suggest that each casein represents a separate gene product, and that the low-molecular-weight proteins are not the result of a post-translational cleavage of the largest. All were distinctly different from the whey protein alpha-lactalbumin.

On the Occurrence and Structure of Subunits of Endopolygalacturonase Isoforms in Mature-Green and Ripening Tomato Fruits

1991 ◽  
Vol 18 (1) ◽  
pp. 65 ◽  
Author(s):  
BJ Pogson ◽  
CJ Brady ◽  
GR Orr
Keyword(s):  
Tomato Fruit ◽  
Exchange Chromatography ◽  
Molecular Forms ◽  
Cation Exchange Chromatography ◽  
Ripe Fruit ◽  
Tomato Fruits ◽  
Green Fruit ◽  
C Terminus ◽  
The One ◽  
Polygalacturonase Activity

Endopolygalacturonase [poly(1,4-α-galacturonide) glycanohydrolase EC 3.2.1.151 occurs in tomato fruit in three molecular forms- PG1, PG2A, PG2B. Trace amounts of PG1, 1-10 pkat g-1 are shown to occur in mature-green fruit as compared to 17 nkat in ripe fruit. As polygalacturonase activity increases through ripening, the percentage of the activity due to PG1 decreases progressively from 100 to less than 20. On fully or partly demethylated substrates, PG1 is more active than PG2 when the ionic strength is that expected in the tissue apoplast. A method for purifying PGI from ripe fruit is described. PG1 preparations contain polypeptides of Mr 45, 43 and 38 thousand. The Mr 43 thousand and 45 thousand components correspond in size to PG2A and PG2B and are detected by antisera raised against PG2A. The M, 38 thousand polypeptide is immunologically distinct. From carbohydrate and amino acid analyses, this polypeptide appears to contain 2870 carbohydrate as glucosamine, mannose, xylose and fucose attached to a polypeptide of estimated Mr 28 342 that is rich in tyrosine and glycine. A method for purifying the subunits of PG1 by cation exchange chromatography in 6 M urea is described. PG2A and PG2B were separated by column chromatography and shown to have identical N-terminal sequences, and serine at the C-terminus. PG2A and PG2B are confirmed as two glycoforms of the one polypeptide. The possibility that PGl consists of populations of molecules containing either PG2A or PG2B coupled with the Mr 38 thousand polypeptide is discussed.

Mitochondrial changes in the guinea-pig muscle after envenomation withVespa orientalis venom

1971 ◽  
Vol 27 (3) ◽  
pp. 303-304 ◽  
Author(s):  
U. Sandbank ◽  
J. Ishay ◽  
S. Gitter
Keyword(s):  
Guinea Pig ◽  
Pig Muscle

scholarly journals Aspergillus oryzae acid proteinase. Purification and properties, and formation of π-chymotrypsin

1975 ◽  
Vol 147 (1) ◽  
pp. 45-53 ◽  
Author(s):  
R Davidson ◽  
A Gertler ◽  
T Hofmann
Keyword(s):  
Aspergillus Oryzae ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Molecular Forms ◽  
Acid Proteinase ◽  
Sedimentation Analysis ◽  
Simple Tool ◽  
Purification And Properties ◽  
Yield And Purity

An acid proteinase from Aspergillus oryzae was isolated from a commercial powder by successive (NH4)2SO4 fractionation, acetone precipitation, and ion-exchange chromatography on phosphate- and DEAE-cellulose columns. The purified enzyme was found to be homogeneous by ultracentrifuge-sedimentation analysis (S20, W equal 3.63S), but electrofocusing in polyacrylamide gels and electrophoresis at pH 3.2 revealed that it consists of two very closely migrating bands. No difference in the amino acid composition and enzymic activities of the two partially separated bands could be detected, and it was concluded that the acid proteinase exists in two molecular forms. The enzyme activates bovine trypsinogen and chymotrypsinogen at pH 3.5 (the kappacat. and Km values at 35degrees C are 11.3S- minus 1, 0.10mM and 1.14S- minus 1, 0.18mM respectively). It hydrolyses the Phe-Phe bond of the synthetic pepsin substrates Z-His-Phe-Phe-OEt (kappacat. equal 1.65S- minus 1, Km equal 0.640mM at pH 3.5, 30degrees C) and Z-Ala-Ala-Phe-Phe-OPy4Pr (kappacat. equal 0.37S- minus 1, Km equal 0.037 mM at pH2.9, 39degrees C), where Z represents benzyloxycarbonyl and OPy4Pr represents 3-(4-pyridyl)-propyl 1-ester. Activation of bovine chymotrypsinogen results from the cleavage of the Arg(15)-Ile(16) bond in the zymogen. No other cleavages were observed. The use of A. oryzae proteinase provides a simple tool for the production of pi-chymotrypsin in good yield and purity.

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