Modulation of broiler plasma metabolic spectrum by the addition of lysine residue to the diet

Author(s):  
Juan Zhang ◽  
Weizhen Wang ◽  
Ying Wang ◽  
Honghong Hu ◽  
Baojun Yu ◽  
...  
Keyword(s):  

1983 ◽  
Vol 49 (03) ◽  
pp. 208-213
Author(s):  
A J Osbahr

SummaryThe modification of canine fibrinogen with citraconic anhydride modified the ε-amino groups of the fibrinogen and at the same time generated additional negative charges into the protein. The addition of thrombin to the modified fibrinogen did not induce polymerization; however, the fibrinopeptide was released at a faster rate than from the unmodified fibrinogen. The physical properties of the citraconylated fibrinogen were markedly altered by the modification of 50-60 lysine residues in one hour. A modified fibrinopeptide-A was released by thrombin from the modified fibrinogen and was electrophoretically more anionic than the unmodified fibrinopeptide-A. Edman analysis confirmed the modification of the lysine residue present in the peptide. The rate of removal of citraconylated fibrinopeptide-A from modified fibrinogen by thrombin was 30 to 40 percent greater than the cleavage of unmodified fibrinopeptide-A from unmodified fibrinogen. However, the modification of 60 or more lysine residues in the fibrinogen produced a decrease in the rate of cleavage of citraconylated fibrinopeptide-A. The results suggest that additional negative charge in the vicinity of the attachment of fibrinopeptide-A to canine fibrinogen aids in the removal of the peptide by thrombin.





Biochemistry ◽  
1983 ◽  
Vol 22 (23) ◽  
pp. 5315-5321 ◽  
Author(s):  
Robert Shapiro ◽  
James F. Riordan


1975 ◽  
Vol 149 (3) ◽  
pp. 627-635 ◽  
Author(s):  
S S Chen ◽  
P C Engel

1. The inactivation of horse liver alcohol dehydrogenase by pyridoxal 5'-phosphate in phosphate buffer, pH8, at 10°C was investigated. Activity declines to a minimum value determined by the pyridoxal 5'-phosphate concentration. The maximum inactivation in a single treatment is 75%. This limit appears to be set by the ratio of the first-order rate constants for interconversion of inactive covalently modified enzyme and a readily dissociable non-covalent enzyme-modifier complex. 2. Reactivation was virtually complete on 150-fold dilution: first-order analysis yielded an estimate of the rate constant (0.164min-1), which was then used in the kinetic analysis of the forward inactivation reaction. This provided estimates for the rate constant for conversion of non-covalent complex into inactive enzyme (0.465 min-1) and the dissociation constant of the non-covalent complex (2.8 mM). From the two first-order constants, the minimum attainable activity in a single cycle of treatment may be calculated as 24.5%, very close to the observed value. 3. Successive cycles of modification followed by reduction with NaBH4 each decreased activity by the same fraction, so that three cycles with 3.6 mM-pyridoxal 5'-phosphate decreased specific activity to about 1% of the original value. The absorption spectrum of the enzyme thus treated indicated incorporation of 2-3 mol of pyridoxal 5'-phosphate per mol of subunit, covalently bonded to lysine residues. 4. NAD+ and NADH protected the enzyme completely against inactivation by pyridoxal 5'-phosphate, but ethanol and acetaldehyde were without effect. 5. Pyridoxal 5'-phosphate used as an inhibitor in steady-state experiments, rather than as an inactivator, was non-competitive with respect to both NADH and acetaldehyde. 6. The partially modified enzyme (74% inactive) showed unaltered apparent Km values for NAD+ and ethanol, indicating that modified enzyme is completely inactive, and that the residual activity is due to enzyme that has not been covalently modified. 7. Activation by methylation with formaldehyde was confirmed, but this treatment does not prevent subsequent inactivation with pyridoxal 5'-phosphate. Presumably different lysine residues are involved. 8. It is likely that the essential lysine residue modified by pyridoxal 5'-phosphate is involved either in binding the coenzymes or in the catalytic step. 9. Less detailed studies of yeast alcohol dehydrogenase suggest that this enzyme also possesses an essential lysine residue.



FEBS Letters ◽  
1996 ◽  
Vol 393 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Klavs Dolmer ◽  
Lise B. Husted ◽  
Peter B. Armstrong ◽  
Lars Sottrup-Jensen
Keyword(s):  


2017 ◽  
Vol 91 (22) ◽  
Author(s):  
Sebastian Rönfeldt ◽  
Barbara G. Klupp ◽  
Kati Franzke ◽  
Thomas C. Mettenleiter

ABSTRACT Newly assembled herpesvirus nucleocapsids are translocated from the nucleus to the cytosol by a vesicle-mediated process engaging the nuclear membranes. This transport is governed by the conserved nuclear egress complex (NEC), consisting of the alphaherpesviral pUL34 and pUL31 homologs. The NEC is not only required for efficient nuclear egress but also sufficient for vesicle formation from the inner nuclear membrane (INM), as well as from synthetic lipid bilayers. The recently solved crystal structures for the NECs from different herpesviruses revealed molecular details of this membrane deformation and scission machinery uncovering the interfaces involved in complex and coat formation. However, the interaction domain with the nucleocapsid remained undefined. Since the NEC assembles a curved hexagonal coat on the nucleoplasmic side of the INM consisting of tightly interwoven pUL31/pUL34 heterodimers arranged in hexamers, only the membrane-distal end of the NEC formed by pUL31 residues appears to be accessible for interaction with the nucleocapsid cargo. To identify the amino acids involved in capsid incorporation, we mutated the corresponding regions in the alphaherpesvirus pseudorabies virus (PrV). Site-specifically mutated pUL31 homologs were tested for localization, interaction with pUL34, and complementation of PrV-ΔUL31. We identified a conserved lysine residue at amino acid position 242 in PrV pUL31 located in the alpha-helical domain H10 exposed on the membrane-distal end of the NEC as a key residue for nucleocapsid incorporation into the nascent primary particle. IMPORTANCE Vesicular transport through the nuclear envelope is a focus of research but is still not well understood. Herpesviruses pioneered this mechanism for translocation of the newly assembled nucleocapsid from the nucleus into the cytosol via vesicles derived from the inner nuclear membrane which fuse in a well-tuned process with the outer nuclear membrane to release their content. The structure of the viral nuclear membrane budding and scission machinery has been solved recently, providing in-depth molecular details. However, how cargo is incorporated remained unclear. We identified a conserved lysine residue in the membrane-distal portion of the nuclear egress complex required for capsid uptake into inner nuclear membrane-derived vesicles.



PLoS ONE ◽  
2018 ◽  
Vol 13 (6) ◽  
pp. e0199686 ◽  
Author(s):  
Abigael C. Songok ◽  
Pradip Panta ◽  
William T. Doerrler ◽  
Megan A. Macnaughtan ◽  
Carol M. Taylor


2004 ◽  
Vol 377 (2) ◽  
pp. 459-467 ◽  
Author(s):  
Jose M. LAPLAZA ◽  
Magnolia BOSTICK ◽  
Derek T. SCHOLES ◽  
M. Joan CURCIO ◽  
Judy CALLIS

In Saccharomyces cerevisiae, the ubiquitin-like protein Rub1p (related to ubiquitin 1 protein) covalently attaches to the cullin protein Cdc53p (cell division cycle 53 protein), a subunit of a class of ubiquitin E3 ligases named SCF (Skp1–Cdc53–F-box protein) complex. We identified Rtt101p (regulator of Ty transposition 101 protein, where Ty stands for transposon of yeast), initially found during a screen for proteins to confer retrotransposition suppression, and Cul3p (cullin 3 protein), a protein encoded by the previously uncharacterized open reading frame YGR003w, as two new in vivo targets for Rub1p conjugation. These proteins show significant identity with Cdc53p and, therefore, are cullin proteins. Modification of Cul3p is eliminated by deletion of the Rub1p pathway through disruption of either RUB1 or its activating enzyme ENR2/ULA1. The same disruptions in the Rub pathway decreased the percentage of total Rtt101p that is modified from approx. 60 to 30%. This suggests that Rtt101p has an additional RUB1- and ENR2-independent modification. All modified forms of Rtt101p and Cul3p were lost when a single lysine residue in a conserved region near the C-terminus was replaced by an arginine residue. These results suggest that this lysine residue is the site of Rub1p-dependent and -independent modifications in Rtt101p and of Rub1p-dependent modification in Cul3p. An rtt101Δ strain was hypersensitive to thiabendazole, isopropyl (N-3-chlorophenyl) carbamate and methyl methanesulphonate, but rub1Δ strains were not. Whereas rtt101Δ strains exhibited a 14-fold increase in Ty1 transposition, isogenic rub1Δ strains did not show statistically significant increases. Rtt101K791Rp, which cannot be modified, complemented for Rtt101p function in a transposition assay. Altogether, these results suggest that neither the RUB1-dependent nor the RUB1-independent form of Rtt101p is required for Rtt101p function. The identification of additional Rub1p targets in S. cerevisiae suggests an expanded role for Rub in this organism.



Sign in / Sign up

Export Citation Format

Share Document