A novel EP-involved pathway for iron release from soya bean seed ferritin

2010 ◽  
Vol 427 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Xiaoping Fu ◽  
Jianjun Deng ◽  
Haixia Yang ◽  
Taro Masuda ◽  
Fumiyuki Goto ◽  
...  
Keyword(s):  
Serine Protease ◽  
Protein A ◽  
Soya Bean ◽  
Iron Release ◽  
Bean Seed ◽  
Specific Domain ◽  
Exterior Surface ◽  
Legume Seeds ◽  
Seedling Germination ◽  
Ph Range

Iron in phytoferritin from legume seeds is required for seedling germination and early growth. However, the mechanism by which phytoferritin regulates its iron complement to these physiological processes remains unknown. In the present study, protein degradation is found to occur in purified SSF (soya bean seed ferritin) (consisting of H-1 and H-2 subunits) during storage, consistent with previous results that such degradation also occurs during seedling germination. In contrast, no degradation is observed with animal ferritin under identical conditions, suggesting that SSF autodegradation might be due to the EP (extension peptide) on the exterior surface of the protein, a specific domain found only in phytoferritin. Indeed, EP-deleted SSF becomes stable, confirming the above hypothesis. Further support comes from a protease activity assay showing that EP-1 (corresponding to the EP of the H-1 subunit) exhibits significant serine protease-like activity, whereas the activity of EP-2 (corresponding to the EP of the H-2 subunit) is much weaker. Consistent with the observation above, rH-1 (recombinant H-1 ferritin) is prone to degradation, whereas its analogue, rH-2, becomes very stable under identical conditions. This demonstrates that SSF degradation mainly originates from the serine protease-like activity of EP-1. Associated with EP degradation is a considerable increase in the rate of iron release from SSF induced by ascorbate in the amyloplast (pH range, 5.8–6.1). Thus phytoferritin may have facilitated the evolution of the specific domain to control its iron complement in response to cell iron need in the seedling stage.

scholarly journals Recent advances in the understanding of trimeric autotransporter adhesins

2019 ◽  
Vol 209 (3) ◽  
pp. 233-242 ◽  
Author(s):  
Andreas R. Kiessling ◽  
Anchal Malik ◽  
Adrian Goldman
Keyword(s):  
Immune System ◽  
Infection Type ◽  
A Priori ◽  
Protein A ◽  
Initial Step ◽  
Infection Process ◽  
Secretion Systems ◽  
Specific Domain ◽  
Recent Advances ◽  
Type V

AbstractAdhesion is the initial step in the infection process of gram-negative bacteria. It is usually followed by the formation of biofilms that serve as a hub for further spread of the infection. Type V secretion systems engage in this process by binding to components of the extracellular matrix, which is the first step in the infection process. At the same time they provide protection from the immune system by either binding components of the innate immune system or by establishing a physical layer against aggressors. Trimeric autotransporter adhesins (TAAs) are of particular interest in this family of proteins as they possess a unique structural composition which arises from constraints during translocation. The sequence of individual domains can vary dramatically while the overall structure can be very similar to one another. This patchwork approach allows researchers to draw conclusions of the underlying function of a specific domain in a structure-based approach which underscores the importance of solving structures of yet uncharacterized TAAs and their individual domains to estimate the full extent of functions of the protein a priori. Here, we describe recent advances in understanding the translocation process of TAAs and give an overview of structural motifs that are unique to this class of proteins. The role of BpaC in the infection process of Burkholderia pseudomallei is highlighted as an exceptional example of a TAA being at the centre of infection initiation.

Effects of graded levels of soya-bean protein on endogenous ileal lysine loss and amino acid digestibility in growing pigs

2005 ◽  
Vol 81 (2) ◽  
pp. 257-264 ◽  
Author(s):  
H. L. Zhang ◽  
S. Y. Qiao ◽  
X. J. Chen ◽  
X. Wang ◽  
J. J. Xing ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Level ◽  
Protein A ◽  
Latin Square ◽  
Protein Product ◽  
Soya Bean ◽  
Growing Pigs ◽  
Protein Levels ◽  
Sigmoid Curve ◽  
Bean Protein

AbstractThis experiment investigated the effects of feeding graded levels of a soya-bean protein product (HP300, Hamlet Protein A/S Company, Denmark) on endogenous ileal lysine loss, apparent ileal amino acid digestibility, standardized true ileal amino acid digestibility determined using the protein-free (PF) method, and real ileal amino acid digestibility determined using the homoarginine (HA) method. The soya-bean protein product was obtained by purifying and defattening soya bean via a proprietary microbial process that decreased the level of trypsin inhibitors and other anti-nutritional factors in soya bean. Six barrows, with an initial body weight of 37·4 ± 1·3 kg, were surgically fitted with simple T-cannulae at the distal ileum and offered six maize-starch-based diets according to a 6 × 6 Latin-square design. The six diets were formulated to provide 0, 50, 100, 150, 200, or 250 g crude protein (CP) per kg by dietary inclusion of 0, 90, 182, 274, 367 or 460 g/kg of soya-bean protein. Five kg of soya-bean protein product was guanidinated in order to estimate endogenous amino acid flow and real ileal amino acid digestibility. Chromium III oxide (5 g/kg) was included in the non-guanidinated diets while dysprosium chloride (0·1 g/kg) was included in the guanidinated diets as an indigestible marker. The experimental periods lasted 8 days. On day 6 of each period, ileal digesta was collected for 24 h to determine apparent and standardized true ileal amino acid digestibility of the non-guanidinated diets. At 08:00 h on day 8, the pigs were given a single meal of the diets containing guanidinated protein and their ileal digesta was collected for 24 h in order to determine the total HA flow and the real ileal digestibility of lysine. Endogenous ileal lysine flow appeared to follow a sigmoid curve starting at about 370 mg/kg dry matter (DM) intake for pigs given the PF diet and continuing asymptotically to about 750 mg/kg DM intake when the inclusion level of the soya-bean protein product was increased to 182 g/kg (100 g/kg of CP). The endogenous ileal lysine flow for pigs given the PF diet was similar (P > 0·05) to that of pigs given 90 g/kg soya-bean protein (50 g/kg of CP) and it increased sharply (P < 0·05) as the level of soya-bean protein increased from 90 to 182 g/kg (50 to 100 g/kg of CP). Thereafter, it was relatively constant (P > 0·05). With an increase in soya-bean protein, there was a quadratic increase (P < 0·01) in the apparent ileal digestibilities for all amino acids except valine and phenylalanine. Standardized true ileal amino acid digestibility decreased (P < 0·05) with an increase in soya-bean protein level. However, real ileal amino acid digestibilities were not influenced (P > 0·05) by soya-bean protein in the diet at levels between 90 and 367 g/kg (50 and 200 g/kg of CP). In conclusion, endogenous ileal lysine flow was not constant and was significantly affected by soya-bean protein level. The results of this study suggest that standardized true ileal amino acid digestibility should be measured between 100 and 200 g/kg of CP (182 and 367 g/kg soya-bean protein) while real ileal amino acid digestibility is unaffected by protein levels between 50 and 200 g/kg of CP (90 and 367 g/kg soya-bean protein).

scholarly journals Fibroblast Activation Protein, a Dual Specificity Serine Protease Expressed in Reactive Human Tumor Stromal Fibroblasts

1999 ◽  
Vol 274 (51) ◽  
pp. 36505-36512 ◽  
Author(s):  
John E. Park ◽  
Martin C. Lenter ◽  
Rainer N. Zimmermann ◽  
Pilar Garin-Chesa ◽  
Lloyd J. Old ◽  
...  
Keyword(s):  
Serine Protease ◽  
Protein A ◽  
Human Tumor ◽  
Fibroblast Activation Protein ◽  
Stromal Fibroblasts ◽  
Fibroblast Activation ◽  
Dual Specificity

scholarly journals Interactions of soya-bean agglutinin with purified glycoconjugates and soya-bean seed components

1985 ◽  
Vol 228 (1) ◽  
pp. 127-136 ◽  
Author(s):  
H M Bond ◽  
M F Chaplin ◽  
D J Bowles
Keyword(s):  
Particulate Matter ◽  
Trichloroacetic Acid ◽  
Lectin Binding ◽  
Soya Bean ◽  
Bean Seed ◽  
Wide Range ◽  
Triton X ◽  
Differential Solubility

A radioaffinity assay for lectin binding to receptors was developed and characterized by using the interactions between soya-bean agglutinin and four glycoconjugates, namely thyroglobulin, galactomannan, fetuin and asialofetuin. On application of the assay to soya-bean extracts a wide range of seed components were found to have the capacity to interact with soya-bean agglutinin. These included both trichloroacetic acid-soluble and trichloroacetic acid-insoluble glycoconjugates and two classes of particulate matter distinguished by their differential solubility in Triton X-100.

Amino acid ileal digestibility of some grain legume seeds in growing chickens

1993 ◽  
Vol 56 (2) ◽  
pp. 261-267 ◽  
Author(s):  
L. Pérez ◽  
I. Fernández-Figares ◽  
R. Nieto ◽  
J. F. Aguilera ◽  
C. Prieto
Keyword(s):  
Amino Acid ◽  
Sole Source ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Field Pea ◽  
Grain Legume ◽  
Legume Seeds ◽  
Bitter Vetch ◽  
Poultry Diets ◽  
Soya Bean Meal

AbstractThe apparent and true amino acid (AA) digestibility from soya-bean meal (SBM), vetch meal (VM), field pea meal (FPM) and bitter vetch meal (BVM) were determined in the lower ileum of growing chickens force-fed on semisynthetic diets (120 g crude protein and 13·1 MJ metabolizable energy per kg dry matter) based on each meal as the sole source of protein. The average apparent and true digestibility values were 0·82, 0·73, 0·76 and 0·60 and 0·90, 0·91, 0·87 and 0·74 for diets SBM, VM, FPM and BVM, respectively. Marked differences in AA digestibility among diets were found. The apparent digestibility of methionine, the most limiting essential AA in poultry diets, was significantly higher in diet SBM than in diets FPM and BVM (P < 0·05). It is concluded that the seeds of vetch and field pea may be suitable for inclusion in poultry diets as partial substitutes for soya bean. The use of bitter vetch is not recommended.

The iron-based phosphate binder PA21 has potent phosphate binding capacity and minimal iron release across a physiological pH range in vitro

2014 ◽  
Vol 81 (04) ◽  
pp. 251-258 ◽  
Author(s):  
Maria Wilhelm ◽  
Sylvain Gaillard ◽  
Viatcheslav Rakov ◽  
Felix Funk
Keyword(s):  
Phosphate Binder ◽  
Binding Capacity ◽  
Iron Release ◽  
Phosphate Binding ◽  
Iron Based ◽  
Ph Range

scholarly journals Characterization of the 4-Hydroxybenzoyl-Coenzyme A Thioesterase from Arthrobacter sp. Strain SU

2003 ◽  
Vol 69 (5) ◽  
pp. 2707-2711 ◽  
Author(s):  
Zhihao Zhuang ◽  
Karl-Heinz Gartemann ◽  
Rudolf Eichenlaub ◽  
Debra Dunaway-Mariano
Keyword(s):  
Coenzyme A ◽  
Sequence Data ◽  
Protein A ◽  
Coa Ligase ◽  
Protein Sequence Data ◽  
Coa Thioesters ◽  
Ph Range ◽  
Rate Profile ◽  
Encoding Genes

ABSTRACT The Arthrobacter sp. strain SU 4-chlorobenzoate (4-CBA) dehalogenation pathway converts 4-CBA to 4-hydroxybenzoate (4-HBA). The pathway operon contains the genes fcbA, fcbB, and fcbC (A. Schmitz, K. H. Gartemann, J. Fiedler, E. Grund, and R. Eichenlaub, Appl. Environ. Microbiol. 58:4068-4071, 1992). Genes fcbA and fcbB encode 4-CBA-coenzyme A (CoA) ligase and 4-CBA-CoA dehalogenase, respectively, whereas the function of fcbC is not known. We subcloned fcbC and expressed it in Escherichia coli, and we purified and characterized the FcbC protein. A substrate activity screen identified benzoyl-CoA thioesters as the most active substrates. Catalysis of 4-HBA-CoA hydrolysis to 4-HBA and CoA occurred with a k cat of 6.7 s−1 and a Km of 1.2 μM. The k cat pH rate profile for 4-HBA-CoA hydrolysis indicated optimal activity over a pH range of 6 to 10. The amino acid sequence of the FcbC protein was compared to other sequences contained in the protein sequence data banks. A large number of sequence homologues of unknown function were identified. On the other hand, the 4-HBA-CoA thioesterases isolated from 4-CBA-degrading Pseudomonas strains did not share significant sequence identity with the FcbC protein, indicating early divergence of the thioesterase-encoding genes.

An Endogenous Protease Activating Plasma Inactive Renin

1978 ◽  
Vol 55 (s4) ◽  
pp. 133s-134s ◽  
Author(s):  
B. J. Leckie
Keyword(s):  
Human Plasma ◽  
Serine Protease ◽  
Protease Inhibitors ◽  
Trypsin Inhibitor ◽  
Soya Bean ◽  
Acid Activation ◽  
Bean Trypsin Inhibitor ◽  
Inactive Renin ◽  
Inhibited Acid ◽  
Endogenous Protease

1. The protease inhibitors Trasylol and soya-bean trypsin inhibitor prevented the activation of plasma inactive renin by acid. 2. N-Ethylmaleimide inhibited acid-activation to some extent but o-phenanthroline had no effect. 3. Acid-activation of the inactive renin in human plasma is mediated by a serine protease.

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