Role of Binding Site Loops in Controlling Nitric Oxide Release:  Structure and Kinetics of Mutant Forms of Nitrophorin 4†,‡

Biochemistry ◽  
2004 ◽  
Vol 43 (21) ◽  
pp. 6679-6690 ◽  
Author(s):  
Estelle M. Maes ◽  
Andrzej Weichsel ◽  
John F. Andersen ◽  
Donald Shepley ◽  
William R. Montfort
1939 ◽  
Vol 17b (3) ◽  
pp. 105-120 ◽  
Author(s):  
E. W. R. Steacie ◽  
H. O. Folkins

An investigation has been made of the inhibition of free radical chain processes in the decomposition of n-butane by the addition of nitric oxide. The method was to initiate chains in butane at low temperatures by means of ethylene oxide, and then to investigate the efficiency of nitric oxide in suppressing these chains.It was found that nitric oxide is not completely efficient as a chain breaker, inasmuch as sensitization by ethylene oxide persisted in the presence of large amounts of nitric oxide. It is therefore concluded that maximum inhibition of organic decomposition reactions by nitric oxide does not in all cases correspond to complete suppression of chains, and hence the real chain length in such reactions may be greater than that inferred from the results of the nitric oxide inhibition method.


2000 ◽  
Vol 35 (3) ◽  
pp. 165-170 ◽  
Author(s):  
M.Brennan Harris ◽  
Hong Ju ◽  
Virginia J. Venema ◽  
Michele Blackstone ◽  
Richard C. Venema

1994 ◽  
Vol 303 (3) ◽  
pp. 831-840 ◽  
Author(s):  
T Sareneva ◽  
J Pirhonen ◽  
K Cantell ◽  
N Kalkkinen ◽  
I Julkunen

Human interferon-gamma (IFN-gamma) is a secretory glycoprotein, which has two potential N-linked glycosylation sites at positions Asn-25 and Asn-97 of its 143 amino acid long mature polypeptide chain. In order to understand the role of glycan residues in the synthesis and secretion of human IFN-gamma, both or either one of the potential N-linked glycosylation sites were mutated to Gln. The mutant and the wild-type (Wt) polypeptides were expressed in insect cells using a baculovirus vector. Elimination of the N-glycosylation site at position Asn-97 (N97Q) resulted in secreted protein yields of 70-90% as compared with the Wt production, whereas only 10-25% (N25Q) and 1-10% (N25Q,N97Q) levels of protein production was observed when the first or both sites were mutated, respectively. Although there was a difference between extracellular levels of produced protein, the kinetics of secretion was similar for all different IFN-gamma molecules. The Wt and the N-glycosylation site mutants were all secreted as dimers. The formation of biologically active dimers was more efficient for IFN-gamma polypeptides that had the intact glycosylation site at Asn-25 as compared with the other two mutant forms of IFN-gamma. The extent of dimerization correlated well with the observed secretion. The specific antiviral activity was of the same order (1 x 10(7) i.u./mg of protein) for the glycosylated IFN-gamma molecules, whereas it was slightly lower (0.5 x 10(7) i.u./mg of protein) for the unglycosylated mutant form.


Neuropeptides ◽  
1998 ◽  
Vol 32 (1) ◽  
pp. 57-62 ◽  
Author(s):  
T Marotti ◽  
T Balog ◽  
R Mažuran ◽  
B Ročić

2021 ◽  
Author(s):  
Ali Imran ◽  
Brandon S. Moyer ◽  
Ashley J. Canning ◽  
Dan Kalina ◽  
Thomas M Duncan ◽  
...  

Recent advances in quantitative proteomics show that WD40 proteins play a pivotal role in numerous cellular networks. Yet, they have been fairly unexplored and their physical associations with other proteins are ambiguous. A quantitative understanding of these interactions has wide-ranging significance. WD40 repeat protein 5 (WDR5) interacts with all members of human SET1/MLL methyltransferases, which regulate methylation of the histone 3 lysine 4 (H3K4). Here, using real-time binding measurements in a high-throughput setting, we identified the kinetic fingerprint of  transient associations between WDR5 and 14-residue WDR5 interaction (Win) motif peptides of each SET1 protein (SET1Win). Our results reveal that the high-affinity WDR5-SET1Win interactions feature slow association kinetics. This finding is likely due to the requirement of SET1Win to insert into the narrow WDR5 cavity, also named the Win binding site. Furthermore, our explorations indicate fairly slow dissociation kinetics. This conclusion is in accordance with the primary role of WDR5 in maintaining the functional integrity of a large multisubunit complex, which regulates the histone methylation. Because the Win binding site is considered a key therapeutic target, the immediate outcomes of this study could form the basis for accelerated developments in medical biotechnology.


2012 ◽  
Vol 74 (1) ◽  
pp. 141-146 ◽  
Author(s):  
R. Preston Mason ◽  
Robert F. Jacob ◽  
Ruslan Kubant ◽  
Adam Jacoby ◽  
Febee Louka ◽  
...  

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