scholarly journals A novel whey protein synthesized only in late lactation by the mammary gland from the tammar (Macropus eugenii)

1987 ◽  
Vol 241 (3) ◽  
pp. 899-904 ◽  
Author(s):  
K R Nicholas ◽  
M Messer ◽  
C Elliott ◽  
F Maher ◽  
D C Shaw

A major whey protein which appears in milk from the tammar wallaby (Macropus eugenii) only during the second half of lactation (late lactation protein-A, LLP-A) was purified to apparent homogeneity by ion-exchange chromatography and gel filtration. An Mr of 21,600 +/- 2000 was calculated from its amino acid composition. A computer-based comparison of the sequence of the first 69 amino acid residues with the Atlas of Protein Sequence data base showed no significant homology with known proteins. Antiserum to LLP-A was prepared in rabbits, and single radial immunodiffusion was used to measure the amounts of LLP-A in milk during the first 40 weeks of lactation. LLP-A was first detected at 26 weeks; thereafter its concentration increased abruptly, to reach a maximum of 26 g/l at approx. 36 weeks of lactation. Explants prepared from mammary gland biopsies at 20 and 35 weeks of lactation were exposed to [3H]amino acids for 8 h; immunoprecipitation of tissue extracts showed that, whereas the rate of casein synthesis was the same at both stages of lactation, LLP-A was synthesized only by the 35-week mammary gland.

1993 ◽  
Vol 4 (3) ◽  
pp. 287-292 ◽  
Author(s):  
D.L. Kauffman ◽  
P.J. Keller ◽  
A. Bennick ◽  
M. Blum

Human proline-rich proteins (PRPs) constitute a complex family of salivary proteins that are encoded by a small number of genes. The primary gene product is cleaved by proteases, thereby giving rise to about 20 secreted proteins. To determine the genes for the secreted PRPs, therefore, it is necessary to obtain sequences of both the secreted proteins and the DNA encoding these proteins. We have sequenced most PRPs from one donor (D.K.) and aligned the protein sequences with available DNA sequences from unrelated individuals. Partial sequence data have now been obtained for an additional PRP from D.K. named II-1. This protein was purified from parotid saliva by gel filtration and ion-exchange chromatography. Peptides were obtained by cleavage with trypsin, clostripain, and N-bromosuccinimide, followed by column chromatography. The peptides were sequenced on a gas-phase protein sequenator. Overlapping peptide sequences were obtained for most of II-1 and aligned with translated DNA sequences. The best fit was obtained with clones containing sequences for the allele PRB4" (Lyons et al., 1988). However, there was not complete identity of the protein amino acid sequence and the DNA-derived sequences, indicating that II-1 is not encoded by PRB4". Other PRPs isolated from D.K. also fail to conform to any DNA structure so far reported. This shows the need to obtain amino acid sequences and corresponding DNA sequences from the same person to assign genes for the PRPs and to determine the location of the postribosomal cleavage points in the primary translation product.


1990 ◽  
Vol 55 (3) ◽  
pp. 846-853 ◽  
Author(s):  
Věra Jonáková ◽  
Brigita Vidimská ◽  
Jana Urbanová ◽  
Manfred Pavlík

Boar proacrosin was purified to apparent homogeneity by a three-step procedure: gel filtration on Sephadex G-50 medium, ion-exchange chromatography on CM-Cellulose 32, and reversed-phase high-performance liquid chromatography on a C4 column. The relative molecular mass (Mr) of the proacrosin estimated by gel filtration was about 70 000, whereas the results of an electrophoretic experiment on SDS-polyacrylamide gel with copolymerized casein under non-reducing conditions indicated an Mr of 55 000-60 000. The proacrosin reproducibly migrated on the gel as a double band. When purified, it remained stable at pH 8.0 for 30 min. The amino-acid composition of the homogeneous proacrosin was determined, the N-terminal amino-acid sequence being Arg-Asp-X-Ala-Thr-X-X-Gly-Pro-X-Gly-.


1979 ◽  
Author(s):  
Takashi Morita ◽  
Craig Jackson

Bovine Factor X is eluted in two forms (X1and X2) from anion exchange chromatographic columns. These two forms have indistinguishable amino acid compositions, molecular weights and specific activities. The amino acid sequences containing the γ-carboxyglutamic acid residues have been shown to be identical in X1 and X2(H. Morris, personal communication). An activation peptide is released from the N-terminal region of the heavy chain of Factor X by an activator from Russell’s viper venom. This peptide can be isolated after activation by gel filtration on Sephadex G-100 under nondenaturing conditions. The activation peptides from a mixture of Factors X1 and X2 were separated into two forms by anion-exchange chromatography. The activation peptide (AP1) which eluted first was shown to be derived from Factor X1. while the activation peptiae (AP2) which eluted second was shown to be derived from X2 on the basis of chromatographic separations carried out on Factors X1 and X2 separately. Factor Xa was eluted as a symmetrical single peak. On the basis of these and other data characterizing these products, we conclude that the difference between X1 and X2 are properties of the structures of the activation peptides. (Supported by a grant HL 12820 from the National Heart, Lung and Blood Institute. C.M.J. is an Established Investigator of the American Heart Association).


1980 ◽  
Vol 187 (3) ◽  
pp. 647-653 ◽  
Author(s):  
K Arakawa ◽  
M Yuki ◽  
M Ikeda

Tryptensin, a vasopressor substance generated from human plasma protein fraction IV-4 by trypsin, has been isolated and the amino acid composition analysed. The procedures used for the isolation were: (a) adsorption of the formed tryptensin on Dowex 50W (X2; NH4+ form); (b) gel filtration through Sephadex G-25; (c) cation-exchange chromatography on CM-cellulose; (d) anion-exchange chromatography on DEAE-cellulose; (e) re-chromatography on CM-cellulose; (f) gel filtration on Bio-Gel P-2; (g) partition chromatography on high-pressure liquid chromatography. The homogeneity of the isolated tryptensin was confirmed by thin-layer chromatography and thin-layer electrophoresis. The amino acid analysis of the hydrolysate suggested the following proportional composition: Asp, 1; Val, 1; Ile, 1; Tyr, 1; Phe, 1; His, 1; Arg, 1; Pro, 1. This composition is identical with that of human angiotensin.


1995 ◽  
Vol 41 (9) ◽  
pp. 1273-1282 ◽  
Author(s):  
Z Chen ◽  
A Prestigiacomo ◽  
T A Stamey

Abstract We describe for the first time a protocol to purify to apparent homogeneity an in vitro-prepared complex of prostate-specific antigen (PSA) and alpha 1-antichymotrypsin (ACT) by using a combination of gel filtration and ion-exchange chromatography. The purity of the PSA-ACT complex was confirmed by gel electrophoresis and Western blot. The PSA-ACT complex was stable in the pH range 6.0 to 7.8; it was also stable in various matrices, temperatures, and high concentrations of salt. Purification of the PSA-ACT complex was highly reproducible. An absorptivity of 0.99 L x g-1 x cm-1 at 280 nm was assigned to the PSA-ACT complex, based on amino acid analysis. Because PSA and ACT bind in a 1:1 molar ratio, we determined the molecular mass of the PSA-ACT complex as the mass encoded by the cDNA of ACT (plus 26% carbohydrate) plus the molecular mass of PSA (28,430 Da), which totals 89,280 Da. Using this material, we made two common calibrators, one of 100% PSA-ACT complex and one of 90% PSA-ACT complex plus 10% free PSA by volume (90:10 calibrator). Substitution of these calibrators for the manufacturers' calibrators in nine commercial immunoassays substantially reduced differences between immunoassays, especially for serum PSA values between 4 and 10 micrograms/L. The 90:10 calibrator is recommended as a universal calibrator for international standardization of PSA immunoassays.


1971 ◽  
Vol 24 (3) ◽  
pp. 765 ◽  
Author(s):  
Jean E Kratzing

The amino acid sequence of the a-chain of haemoglobin from M. giganteus has been determined. The soluble peptides formed by tryptic digestion were isolated by gel filtration, ion-exchange chromatography, paper ionophoresis, and chromatography. The amino acid sequences were determined by the "dansyl"Edman procedure. Incomplete hydrolysis of one bond resulted in a large insolublecore peptide containing 40 amino acid residues. The sequence of this peptide was deduced from the sequences of smaller peptides resulting from further digestion with thermolysin and papain. Maleylation of the a-globin before tryptic digestion gave three large fragments which assisted in assigning tryptic peptides to specific areas of the molecule. A special procedure involving maleylation of a chymotryptic digest of globin was used to isolate peptides containing arginine which provided overlap sequences of tryptic peptides


2001 ◽  
Vol 47 (8) ◽  
pp. 767-772 ◽  
Author(s):  
A KM Shofiqur Rahman ◽  
Shinya Kawamura ◽  
Masahiro Hatsu ◽  
M M Hoq ◽  
Kazuhiro Takamizawa

The zygomycete fungus Rhizomucor pusillus HHT-1, cultured on L(+)arabinose as a sole carbon source, produced extracellular α-L-arabinofuranosidase. The enzyme was purified by (NH4)2SO4fractionation, gel filtration, and ion exchange chromatography. The molecular mass of this monomeric enzyme was 88 kDa. The native enzyme had a pI of 4.2 and displayed a pH optimum and stability of 4.0 and 7.0–10.0, respectively. The temperature optimum was 65°C, and it was stable up to 70°C. The Kmand Vmaxfor p-nitrophenyl α-L-arabinofuranoside were 0.59 mM and 387 µmol·min–1·mg–1protein, respectively. Activity was not stimulated by metal cofactors. The N-terminal amino acid sequence did not show any similarity to other arabinofuranosidases. Higher hydrolytic activity was recorded with p-nitrophenyl α-L-arabinofuranoside, arabinotriose, and sugar beet arabinan; lower hydrolytic activity was recorded with oat–spelt xylan and arabinogalactan, indicating specificity for the low molecular mass L(+)-arabinose containing oligosaccharides with furanoside configuration.Key words: α-L-arabinofuranosidase, enzyme purification, amino acid sequence, Rhizomucor pusillus.


1995 ◽  
Vol 305 (1) ◽  
pp. 145-150 ◽  
Author(s):  
P J Fitzpatrick ◽  
T O B Krag ◽  
P Højrup ◽  
D Sheehan

The major isoenzyme of glutathione S-transferase (GST 1) was purified to homogeneity from cytosolic extracts of Mytilus edulis gill tissue by GSH-agarose affinity chromatography followed by Mono Q ion-exchange f.p.l.c. This enzyme was particularly active with 1-chloro-2,4-dinitrobenzene, ethacrynic acid and cumene hydroperoxide as substrates. Immunoblotting and amino acid sequencing studies indicate that the enzyme belongs to the Pi class of GSTs. A related protein which binds to GSH-agarose was also purified. This GSH-binding protein did not immunoblot with GST antisera and showed no detectable catalytic activity with GST substrates although its N-terminal sequence was similar to Mu-class GSTs. Gel-filtration chromatography indicated that GST 1 is a dimer and the GSH-binding protein a monomer. Mass spectrometry and SDS/PAGE indicate subunit molecular masses of 24 kDa (GST 1) and 25 kDa (GSH-binding protein), respectively. Both proteins have amino acid compositions typical of GSTs.


1979 ◽  
Author(s):  
Takashi Morita ◽  
Craig M. Jackson

Bovine Factor X is eluted in two forms (X1 and X2) from anion exchange chromatographic columns. These two forms have indistinguishable amino acid compositions, molecular weights and specific activities. The amino acid sequences containing the γ-carboxyglu-tamic acid residues have been shown to be identical in X1 and X2, (H. Morris, personal communication). An activation peptide is released from the N-terminal region of the heavy chain of Factor X by an activator from Russell’s viper venom. This peptide can be isolated after activation by gel filtration on Sephadex G-100 under nondenaturing conditions. The activation peptides from a mixture of Factors X1 and X2 were separated into two forms by an ion-exchange chromatography. The activation peptide AP1) which eluted first was shown to be derived from Factor X1 while the activation peptide (AP2) which eluted second was shown to be derived from X2 on basis of chromatographic separations carried out on Factors X1 and X2 separately. Factor Xa was eluted as a symmetrical single peak. On the basis of these and other data characterizing these products, we conclude that the difference between X1 and X2 are properties of the structures of the activation peptides. (Supported by a grant HL 12820 from the National Heart, Lung and Blood Institute. C.H.J. is an Established Investigator of the American Heart Association).


1979 ◽  
Vol 83 (1) ◽  
pp. 79-89 ◽  
Author(s):  
C. SERNIA ◽  
C. H. TYNDALE-BISCOE

SUMMARY Specific binding of radio-iodinated ovine prolactin to subcellular tissue fractions of the tammar wallaby (Macropus eugenii) was investigated. Specific binding was found, in order of decreasing binding activity, in the lactating mammary gland, corpus luteum, corpus albicans, adrenal gland and ovary. Specific binding was absent in kidney, liver, brain and inactive mammary gland. The mean association constant (Ka at 23 °C) was determined as 0·90 × 109, 2·20 × 109, 2·44 × 109, 3·38 × 109 and 10·98 × 1091/mol for mammary gland, adrenal, corpus albicans, corpus luteum and ovary respectively. The mean receptor concentration (N) varied from 92·87 × 10−14 mol/mg protein for the mammary gland to 1·03 × 10−14 mol/mg protein for the ovary. The concentration in the corpus luteum varied between tissue pools collected at different times of the annual breeding cycle. The specificity for prolactin was shown in the mammary gland and corpus luteum by the failure of ovine FSH, LH, GH and TSH to displace 125I-labelled ovine prolactin, whereas it was displaced readily by both ovine and bovine prolactin.


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