scholarly journals Relationship between biotin-binding proteins from chicken plasma and egg yolk

1978 ◽  
Vol 175 (2) ◽  
pp. 629-633 ◽  
Author(s):  
R D Mandella ◽  
H W Meslar ◽  
H B White
Keyword(s):  
Binding Proteins ◽  
Elevated Temperatures ◽  
Binding Protein ◽  
Gel Filtration ◽  
Egg Yolk ◽  
Egg White ◽  
Similar Molecular Weight ◽  
Precipitin Line ◽  
Ion Exchange Column ◽  
Biotin Binding

The plasma of laying hens contains a specific biotin-binding protein that appears to be identical with an egg-yolk biotin-binding protein. Both proteins are saturated with biotin and require elevated temperatures to effect the exchange of [14C]biotin for the protein-bound vitamin. The heat-exchange curve in each case is the same and differs sharply from that of avidin, the egg-white biotin-binding protein. On Sephadex G-100 gel filtration, plasma and yolk biotin-binding proteins were each eluted slightly ahead of avidin (mol.wt. 68,000), suggesting that they are of similar molecular weight. Plasma and yolk biotin-binding proteins required the same ionic strength to be eluted from a phosphocellulose ion-exchange column. Both the plasma and yolk biotin-binding proteins had a pI of 5; avidin has a pI of 10. Plasma biotin-binding protein cross-reacted with antiserum to yolk biotin-binding protein and showed a precipitin line of identity with purified yolk biotin-binding protein. It is suggested that biotin-binding plays an important role in mediating the transport of the vitamin from the bloodstream to the developing oocyte.

scholarly journals Biotin-binding protein from chicken egg yolk. Assay and relationship to egg-white avidin

1976 ◽  
Vol 157 (2) ◽  
pp. 395-400 ◽  
Author(s):  
H B White ◽  
B A Dennison ◽  
M A Della Fera ◽  
C J Whitney ◽  
J C McGuire ◽  
...  
Keyword(s):  
Binding Protein ◽  
Gel Filtration ◽  
Egg Yolk ◽  
Egg White ◽  
Specific Protein ◽  
Chicken Egg ◽  
Biotin Binding ◽  
Lower Temperature ◽  
Chicken Egg Yolk ◽  
Kinetics Of

1. Biotin in chicken egg yolk is non-covalently bound to a specific protein that comprises 0.03% of the total yolk protein (0.8 mg/yolk). This biotin-binding protein is not detectable by the normal avidin assay owing to the biotin being tightly bound. Exchange of [14C]biotin for bound biotin at 65 degrees C is the basis of an assay for this protein. 2. Biotin-binding protein from egg yolk is distinguishable from egg-white avidin on Sephadex G-100 gel filtration, although the sizes of the two proteins appear quite similar. 3. Biotin-binding protein is denatured at a lower temperature and freely exchanges biotin at lower temperatures than does avidin. 4. The biotin-binding protein in egg yolk is postulated to be responsible for the deposition of biotin in egg yolk. D-[carboxyl-14C]Biotin injected into laying hens rapidly appears in the egg bound to yolk biotin-binding protein and avidin. Over 60% of the radioactivity is eventually deposited in eggs. The kinetics of biotin deposition in the egg suggests a 25 day half-life for an intracellular biotinyl-coenzyme pool in the laying hen.

Zinc- and copper-binding proteins in the plasma of winter flounder (Pseudopleuronectes americanus)

1980 ◽  
Vol 58 (4) ◽  
pp. 609-613 ◽  
Author(s):  
P. E. Fletcher ◽  
G. L. Fletcher
Keyword(s):  
Molecular Weight ◽  
Binding Proteins ◽  
Binding Protein ◽  
Gel Filtration ◽  
Protein S ◽  
Egg Yolk ◽  
Winter Flounder ◽  
Zinc Binding ◽  
Copper Binding ◽  
Copper Binding Proteins

Zinc- and copper-binding proteins were isolated from the plasma of winter flounder using gel filtration chromatography. A single copper-binding protein fraction of molecular weight 170 000 was isolated from the plasma of both sexes.In male and female flounder over 95% of the plasma zinc was associated with a zinc-binding protein(s) with a molecular weight of 76 000. In male flounder the remaining zinc appeared to be bound to a protein(s) of molecular weight 186 000. In female flounder the remaining 5% of the zinc was associated with two zinc-binding fractions with apparent molecular weights of 186 000 and 340 000 – 370 000.Extracts of plasma vitellogenin and egg yolk proteins revealed significant quantities of zinc and copper. It is hypothesized that the female specific zinc-binding protein (340 000 – 370 000) was vitellogenin.

scholarly journals Biotin-binding protein from egg yolk. A protein distinct from egg white avidin.

1978 ◽  
Vol 253 (19) ◽  
pp. 6979-6982 ◽  
Author(s):  
H.W. Meslar ◽  
S.A. Camper ◽  
H.B. White
Keyword(s):  
Binding Protein ◽  
Egg Yolk ◽  
Egg White ◽  
Biotin Binding

Comparisons of various acidic treatments of bovine serum on insulin-like growth factor-I immunoreactivity and binding activity

1990 ◽  
Vol 127 (1) ◽  
pp. 139-148 ◽  
Author(s):  
C. Y. Lee ◽  
D. M. Henricks
Keyword(s):  
Growth Factor ◽  
Bovine Serum ◽  
Binding Proteins ◽  
Binding Protein ◽  
Gel Filtration ◽  
Binding Activity ◽  
Insulin Like Growth Factor ◽  
Ethanol Extraction ◽  
Factor I ◽  
Igf I

ABSTRACT Untreated serum exhibited two forms of insulin-like growth factor-I (IGF-I)-binding protein complexes during gel chromatography: one of Mr 150 000 and the other of Mr 40 000–45 000. The majority of the immunoreactive IGF-I was associated with the Mr 150 000 complex. Following acid-ethanol extraction of serum, the binding activity at Mr 150 000 disappeared and a reduced binding activity appeared in the albumin size range. Acid incubation of serum was slightly less effective than acid-ethanol extraction in reducing the binding activity. Acid-ethanol-extracted or acid-incubated serum were parallel to IGF-I standard in the dose–response displacement of iodinated IGF-I. Gel filtration of serum with 1 mol acetic acid/l almost completely separated IGF-I and the binding proteins. Binding-protein fractions from gel filtration interfered with the immunoreactivity of IGF-I with its antibodies, causing a non-parallel displacement curve in the radioimmunoassay (RIA). Serum IGF-I could be isolated as a single peak by high performance C18 reverse-phase liquid chromatography (HPLC). The concentrations of IGF-I measured in bovine sera by RIA were similar between acid gel filtration and HPLC; the concentrations by acid-ethanol extraction and acid incubation being about 30% smaller than those measured with former methods. The lower concentration of IGF-I measured in bovine serum with acid-ethanol extraction or acid incubation appears to be due to interference of IGF-binding proteins not removed by either treatment. Journal of Endocrinology (1990) 127, 139–148

scholarly journals Role of avidin and other biotin-binding proteins in the deposition and distribution of biotin in chicken eggs. Discovery of a new biotin-binding protein

1987 ◽  
Vol 241 (3) ◽  
pp. 677-684 ◽  
Author(s):  
H B White ◽  
C C Whitehead
Keyword(s):  
Laying Hens ◽  
Protein Complexes ◽  
Binding Protein ◽  
Egg Yolk ◽  
Heat Stability ◽  
Plasma Vitamin ◽  
Dietary Intakes ◽  
Adult Males ◽  
Biotin Binding ◽  
Maximal Production

In addition to the previously characterized egg-yolk biotin-binding protein (BBP-I), we have discovered another BBP (BBP-II) in the plasma and yolk from laying hens. BBP-I is stable to 65 degrees C, whereas BBP-II is stable to 45 degrees C. Both proteins are normally saturated with biotin and together they account for most, if not all, of the biotin in hen plasma and yolk, except in hens fed excessive amounts of biotin (greater than 1 mg of biotin/kg of feed). The maximal production of BBP-I is attained at lower levels of dietary biotin (approximately 50 micrograms/kg) than for BBP-II (approximately 250 micrograms/kg); however, the maximal production of BBP-II is severalfold greater than for BBP-I. Consequently, as dietary biotin increases, the ratio of BBP-II to BBP-I increases and becomes constant at dietary intakes of biotin above 250 micrograms/kg. The observation that the amounts of these proteins are limited by biotin in the normal dietary range (less than 250 micrograms/kg) suggests that biotin is required for the synthesis, secretion or stability of these proteins. Although both plasma vitamin-protein complexes are transported to the oocyte and concentrated in the yolk, BBP-II is transferred more efficiently. Thus biotin deposition in the yolk is a function of the amounts and relative concentrations of the two proteins. Dietary biotin above 250 micrograms/kg exceeds the transport capacity of BBP-I and BBP-II in the plasma; however, unbound biotin does not accumulate. Rather it is efficiently scavenged by avidin in the oviduct and transferred to the egg albumen. Only when avidin becomes saturated at high dietary intake does free or weakly bound biotin accumulate in plasma and yolk. The synthesis of avidin is independent of dietary biotin. Small amounts of BBPs with the heat-stability of avidin or BBP-I respectively are present in the plasma of adult males or immature chickens. BBP-II, the major BBP in the plasma and yolk of laying hens, was not detected in the plasma of non-laying chickens.

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.

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