scholarly journals Isolation and Characterization of the Vascular-specific 22-kDa Zn-binding Protein

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 475D-475
Author(s):  
Kathryn C. Taylor ◽  
Danielle R. Elli
Keyword(s):  
Amino Acid ◽  
Metal Binding ◽  
Binding Protein ◽  
Xylem Sap ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Ancestral Gene ◽  
Rangpur Lime ◽  
Rough Lemon ◽  
Isolation And Characterization

A 22-kDa Zn-binding protein (ZBP) was isolated from the phloem tissue and evacuated xylem sap of `Valencia' sweet orange [Citrus sinensis (L.) Osbeck] on rough lemon [C. jambhiri (L.)], as well as Valencia on Rangpur lime [Citrus limonia Osbeck]. Phloem and xylem Zn was associated with the 22 kDa ZBP. The Mr value of this ZBP was estimated to be 19,500 by size exclusion chromatography and 22,800 by SDS-PAGE. This protein was isolated with an isoelectric point of 7.5. Ion exchange chromatography demonstrated that 22-kDa ZBP was highly anionic, requiring 0.43 M NaCl for elution from QAE Sepharose. The 22-kDa ZBP appears unique to citrus, having no cross reaction with protein from several tissues from a range of plant species. Accumulation decreased under Zn-deficient conditions, was enhanced by osmotic stress, and the protein completely disappeared with wounding. Amino acid composition demonstrated that the protein was rich in aspartate, and glutamate; and contained 6 cysteine, and 4 histidine residues. These amino acids may be involved in metal binding. N-terminal amino acid sequencing demonstrated that the 22-kDa ZBP had identity with sporamin A&B precursors, Kunitz-type trypsin inhibitors, and miraculin. It is suggested that the genes that encode these proteins are derived from a common ancestral gene.

scholarly journals Cadmium-binding proteins of rat testes. Apparent source of the protein of low molecular mass

1984 ◽  
Vol 220 (3) ◽  
pp. 819-824 ◽  
Author(s):  
M P Waalkes ◽  
S B Chernoff ◽  
C D Klaassen
Keyword(s):  
Amino Acid ◽  
Metal Binding ◽  
Amino Acid Analysis ◽  
Binding Proteins ◽  
Binding Protein ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Breakdown Product ◽  
Heat Stable ◽  
Metal Binding Protein

Fractionation of rat testicular cytosolic proteins by gel filtration indicates three major metal-binding proteins, or groups of proteins, termed testicular metal-binding protein (TMBP) 1, 2 and 3 by order of elution. The major heat-stable, metal-binding proteins in testes is TMBP-2, which has an Mr of approx. 25000. In most tissues, metallothionein (MT) is the major heat-stable, metal-binding protein, but it has an Mr of 6000. This testicular protein (TMBP-2) is much larger than MT, and since polymeric forms of MT have been previously reported, further characterization of TMBP-2 was performed. TMBP-2 was separated into two forms by DEAE-Sephadex A-25 anion-exchange chromatography. Amino acid analysis of both forms of TMBP-2 revealed that they differed markedly from MT, having particularly low cysteine contents. However, amino acid analysis showed that TBMP-2 was strikingly similar to TMBP-3, with an approximate stoichiometric relationship of 4:1. Therefore, experiments were conducted to determine if TMBP-3 could be a breakdown product of TMBP-2. Heat treatment of testicular cytosol in room air before gel filtration resulted in a marked increase in TMBP-3 and loss of TMBP-2. Storing intact testes at −20 degrees C for 2 weeks before processing for gel filtration also resulted in an increase in TMBP-3 and a loss of TMBP-2. Addition of a reducing agent (dithiothreitol) or proteinase inhibitor (N-ethylmaleimide) in processing of samples before gel filtration inhibited the appearance of TMBP-3. Results suggest that the low-Mr Cd-binding protein (TMBP-3) of rat testes results from either proteolytic or oxidative breakdown of a higher-Mr species, or from a combination of such factors.

scholarly journals Isolation and characterization of pig enamelins

1987 ◽  
Vol 243 (2) ◽  
pp. 385-390 ◽  
Author(s):  
H Limeback
Keyword(s):  
Amino Acid ◽  
Gel Electrophoresis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Binding Studies ◽  
Isolation And Characterization ◽  
Sequential Extraction Procedures ◽  
Enamel Proteins

Enamel proteins were extracted from pig developing enamel by sequential extraction procedures. Two proteins identified as enamelins by slab-gel electrophoresis (Mr 67,000 and 63,000) were separated from amelogenins by gel sieving and ion-exchange chromatography. Their enamelin characteristic was confirmed by hydroxyapatite-binding studies and amino acid analysis. Degradation of extracted enamel proteins was also studied in vitro. The larger of the two enamelins appeared to be resistant to degradation by endogenous enamel proteinases. Hydroxyapatite showed strong binding with the enamelins, but did not prevent the degradation of the Mr-63,000 enamelin. These results indicate that at least one high-Mr enamelin in pig developing enamel is a source of enamelin breakdown products.

scholarly journals Isolation and characterization of a laminin-binding protein from rat and chick muscle.

1988 ◽  
Vol 107 (2) ◽  
pp. 687-697 ◽  
Author(s):  
D E Hall ◽  
K A Frazer ◽  
B C Hann ◽  
L F Reichardt
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Amino Acid ◽  
Binding Protein ◽  
Light And Electron Microscopy ◽  
Muscle Membrane ◽  
Total Amino Acid ◽  
Isolation And Characterization ◽  
Laminin Binding Protein ◽  
Laminin Binding

A major laminin-binding protein (LBP), distinct from previously described LBPs, has been isolated from chick and rat skeletal muscle (Mr 56,000 and 66,000, respectively). The purified LBPs from the two species were shown to be related antigenically and to have similar NH2-terminal amino acid sequences and total amino acid compositions. Protein blots using laminin and laminin fragments provided evidence that this LBP interacts with the major heparin-binding domain, E3, of laminin. Studies on the association of this LBP with muscle membrane fractions and reconstituted lipid vesicles indicate that this protein can interact with lipid bilayers and has properties of a peripheral, not an integral membrane protein. These properties are consistent with its amino acid sequence, determined from cDNAs (Clegg et al., 1988). Examination by light and electron microscopy of the LBP antigen distribution in skeletal muscle indicated that the protein is localized primarily extracellularly, near the extracellular matrix and myotube plasmalemma. While a form of this LBP has been identified in heart muscle, it is present at low or undetectable levels in other tissues examined by immunocytochemistry indicating that it is probably a muscle-specific protein. As this protein is localized extracellularly and can bind to both membranes and laminin, it may mediate myotube interactions with the extracellular matrix.

scholarly journals Primary structure and tissue-specific expression of blue crab (Callinectes sapidus) metallothionein isoforms

1995 ◽  
Vol 311 (2) ◽  
pp. 617-622 ◽  
Author(s):  
M Brouwer ◽  
J Enghild ◽  
T Hoexum-Brouwer ◽  
I Thogersen ◽  
A Truncali
Keyword(s):  
Anion Exchange ◽  
Blue Crab ◽  
Metal Binding ◽  
Binding Proteins ◽  
Callinectes Sapidus ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Specific Expression ◽  
Tissue Specific ◽  
Metallothionein Isoforms

In aquatic animals, synthesis of the metal-binding protein metallothionein (MT) can be induced through exposure to elevated levels of metals in food or water. Whether the different routes of exposure lead to expression of different metallothionein isoforms in different tissues in unknown. In this study we examined the induction of metallothionein isoforms in the hepatopancreas and gills of the blue crab Callinectes sapidus. When blue crabs are exposed to cadmium in their diet, the metal accumulates in the hepatopancreas. Size-exclusion and anion-exchange chromatography show the presence of five low-molecular-mass cadmium-binding proteins. All of the observed cadmium-binding proteins belong to the class I MT family. They are designated as MT-Ia, MT-Ib, MT-Ic, MT-IIa and MT-IIb. All purified proteins run as single peaks upon rechromatography on anion-exchange HPLC, except for MT-Ic, which segregates into two peaks corresponding to MT-Ia and MT-Ic. The amino acid sequence of MT-Ia and MT-Ic is identical. MT-Ib differs from MT-Ia and MT-Ic only in having an extra N-terminal methionine. The 18 cysteine residues in MT-Ia and MT-IIa occur in identical positions; however, of the remaining 40 amino acids, 15 are found to be different. MT-IIb is identical with MT-IIa, except for an extra methionine residue at its N-terminal position. It appears therefore that, of the five observed CdMTs, only two are the products of distinct genes. CdMT-Ia and -IIa are posttranslationally modified forms of Ib and IIb, respectively, and CdMT-Ia and -Ic appear to be conformational isomers. Cadmium-induced expression of the two genes is tissue-specific. When crabs are exposed to cadmium in water, the metal accumulates in the gills, where it is bound to MT-II. MT-I is virtually absent.

scholarly journals Separation and characterization of the two Asn-linked glycosylation sites of chicken serum riboflavin-binding protein. Glycosylation differences despite similarity of primary structure

1992 ◽  
Vol 285 (1) ◽  
pp. 275-280 ◽  
Author(s):  
J S Rohrer ◽  
H B White
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Primary Structure ◽  
Tertiary Structure ◽  
Binding Protein ◽  
Attachment Site ◽  
Reversed Phase ◽  
Exchange Chromatography ◽  
Protein Glycosylation ◽  
Oligosaccharide Structure

Serum riboflavin-binding protein, a phosphoglycoprotein from the blood of laying hens, contains two Asn-Xaa-(Thr)Ser sequons in very similar but well-separated regions of amino acid sequence. In order to evaluate the effect of local amino acid sequence on the structure of the attached oligosaccharides, serum riboflavin-binding protein was purified to homogeneity, reduced and alkylated, digested with trypsin, and the two glycopeptides were separated by reversed-phase chromatography. After digestion with peptide-N-glycosidase F the released oligosaccharides were separated by high-pH anion-exchange chromatography and the oligosaccharide profiles of the two glycopeptides were compared. Although the two asparagine residues that are glycosylated are contained in pentapeptide segments in which four out of five amino acids are identical, the array of oligosaccharides present at each site show differences in both type and distribution. This suggests that local secondary or tertiary structure, or the order of glycosylation, influences the oligosaccharide structure more than does the primary structure flanking the attachment site.

scholarly journals Hagfish slime gland thread cells. II. Isolation and characterization of intermediate filament components associated with the thread.

1984 ◽  
Vol 98 (2) ◽  
pp. 670-677 ◽  
Author(s):  
R H Spitzer ◽  
S W Downing ◽  
E A Koch ◽  
W L Salo ◽  
L J Saidel
Keyword(s):  
Amino Acid ◽  
Present Report ◽  
Amino Acid Content ◽  
Cell Types ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Isolation And Characterization ◽  
Hydroxyamino Acids ◽  
Isoelectric Ph

The slime glands of hagfish have two major cell types, gland thread cells (GTCs) and gland mucous cells (GMCs), both of which upon contact with water contribute to the formation of an abundant quantity of viscous mucus. In previous studies we reported a method for the isolation of GTCs and showed that each ellipsoidal thread cell normally contains a single tapered thread which is uniquely coiled into a space-saving conformation and occupies most of the cell volume. Subsequently, the developing thread was found to consist mainly of intermediate filaments (IFs) aligned in parallel not only to one another but also to a far fewer number of interspersed microtubules (see accompanying paper). In the present report, urea extracts of GTCs were purified and characterized to establish the properties of thread components. One major (alpha) and two minor (beta, gamma) components prepared by anion exchange chromatography were shown to have similar apparent molecular weights of 63,500 +/- 500 daltons but different isoelectric pH values (alpha, 7.56; beta, 5.67; gamma, 5.31). Although the amino acid content of alpha differed significantly from beta and gamma, each of the three was highest in Gly, relatively high in Glx, Ser, Thr, Asx, Ala, Val, and Leu, and relatively low in Cys/2 and Trp. The amino acid compositions of beta and gamma were very similar, and only beta showed evidence of carbohydrate. The threonine content of the alpha component was higher than has been reported for IFs of different origin, and the high content of hydroxyamino acids (18, 19 residues per 100) in alpha, beta, and gamma has been approached only by several IF polypeptides from human or bovine epidermal keratins. Mixtures of the purified components formed 9-11-nm filaments in vitro. The results indicate that the hagfish thread cell is a rich source of IFs, which have a structure that facilitates formation of macrofibrils within the cell.

Structure-based characterization and antifreeze properties of a hyperactive ice-binding protein from the Antarctic bacteriumFlavobacterium frigorisPS1

2014 ◽  
Vol 70 (4) ◽  
pp. 1061-1073 ◽  
Author(s):  
Hackwon Do ◽  
Soon-Jong Kim ◽  
Hak Jun Kim ◽  
Jun Hyuck Lee
Keyword(s):  
Amino Acid ◽  
Binding Site ◽  
Disulfide Bond ◽  
Binding Protein ◽  
Size Exclusion ◽  
Sequence Alignments ◽  
Ice Binding ◽  
Ice Binding Protein ◽  
Binding Residues ◽  
The Antarctic

Ice-binding proteins (IBPs) inhibit ice growth through direct interaction with ice crystals to permit the survival of polar organisms in extremely cold environments. FfIBP is an ice-binding protein encoded by the Antarctic bacteriumFlavobacterium frigorisPS1. The X-ray crystal structure of FfIBP was determined to 2.1 Å resolution to gain insight into its ice-binding mechanism. The refined structure of FfIBP shows an intramolecular disulfide bond, and analytical ultracentrifugation and analytical size-exclusion chromatography show that it behaves as a monomer in solution. Sequence alignments and structural comparisons of IBPs allowed two groups of IBPs to be defined, depending on sequence differences between the α2 and α4 loop regions and the presence of the disulfide bond. Although FfIBP closely resemblesLeucosporidium(recently re-classified asGlaciozyma) IBP (LeIBP) in its amino-acid sequence, the thermal hysteresis (TH) activity of FfIBP appears to be tenfold higher than that of LeIBP. A comparison of the FfIBP and LeIBP structures reveals that FfIBP has different ice-binding residues as well as a greater surface area in the ice-binding site. Notably, the ice-binding site of FfIBP is composed of a T-A/G-X-T/N motif, which is similar to the ice-binding residues of hyperactive antifreeze proteins. Thus, it is proposed that the difference in TH activity between FfIBP and LeIBP may arise from the amino-acid composition of the ice-binding site, which correlates with differences in affinity and surface complementarity to the ice crystal. In conclusion, this study provides a molecular basis for understanding the antifreeze mechanism of FfIBP and provides new insights into the reasons for the higher TH activity of FfIBP compared with LeIBP.

scholarly journals Isolation and Characterization of a Novel Sialoglycopeptide Promoting Osteogenesis from Gadus morhua Eggs

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 156
Author(s):  
Zhiliang Hei ◽  
Meihui Zhao ◽  
Yingying Tian ◽  
Hong Chang ◽  
Xuanri Shen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gadus Morhua ◽  
Bone Growth ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Isolation And Characterization

Gadus morhua eggs contain several nutrients, including polyunsaturated fatty acids, lecithin and glycoproteins. A novel sialoglycopeptide from the eggs of G. morhua (Gm-SGPP) was extracted with 90% phenol and purified by Q Sepharose Fast Flow (QFF) ion exchange chromatography, followed by S-300 gel filtration chromatography. Gm-SGPP contained 63.7% carbohydrate, 16.2% protein and 18.6% N-acetylneuraminic acid. High-performance size exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that Gm-SGPP is a 7000-Da pure sialoglycopeptide. β-elimination reaction suggested that Gm-SGPP contained N-glycan units. Amino acid N-terminal sequence analysis indicated the presence of Ala-Ser-Asn-Gly-Thr-Gln-Ala-Pro amino acid sequence. Moreover, N-glycan was connected at the third Asn location of the peptide chain through GlcNAc. Gm-SGPP was composed of D-mannose, D-glucuronic acid and D-galactose. Fourier transform-infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance spectroscopy (1H-NMR) and methylation analysis were performed to reveal the structure profile of Gm-SGPP. In vitro results showed that the proliferation activity of MC3T3-E1 cells was significantly promoted by Gm-SGPP. In vivo data revealed that Gm-SGPP increased the calcium and phosphorus content of tibias and promoted longitudinal bone growth in adolescent rats.

Isolation and characterization of antifreeze glycoproteins from the frostfish, Microgadus tomcod

1982 ◽  
Vol 60 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Garth L. Fletcher ◽  
Choy L. Hew ◽  
Shashikant B. Joshi
Keyword(s):  
Amino Acid ◽  
High Performance ◽  
Antifreeze Proteins ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Antifreeze Glycoproteins ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
Saffron Cod ◽  
Microgadus Tomcod

The antifreeze proteins were isolated from frostfish (Microgadus tomcod) using gel filtration and ion exchange chromatography and characterized by high-performance liquid chromatography. The antifreeze proteins were glycoproteins which appeared to consist of at least six components with molecular weights ranging from 2 550 to 32 200. Chemical analysis of the larger components showed a predominance of alanine, threonine, and galactosamine. The smaller peptides contained proline and arginine in addition to alanine and threonine. The amino acid sequence of the smallest glycopeptides (molecular weight 2 550) was found to be Ala-Ala-Thr-Ala-Ala-Thr-[Formula: see text]-Ala-Thr-Ala-Ala-Thr-Pro-Ala-[Formula: see text]-Ala-Ala.These glycopeptides are very similar in amino acid and carbohydrate composition to those isolated from the Antarctic nototheniids and several northern gadoids. The sequence of the first 14 amino acids of smaller glycopeptides from the frostfish is identical to comparable peptides found in the nototheniids and the saffron cod. To date arginine has only been observed in the glycopeptide antifreezes of the frostfish and the saffron cod.

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