Four Amino Acid Residues Influence the Substrate Chain-Length and Regioselectivity of Siganus canaliculatus Δ4 and Δ5/6 Desaturases

Lipids ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 357-367 ◽  
Author(s):  
Ze Long Lim ◽  
Toralf Senger ◽  
Patricia Vrinten
1986 ◽  
Vol 71 (1) ◽  
pp. 65-69 ◽  
Author(s):  
G. K. Grimble ◽  
P. P. Keohane ◽  
B. E. Higgins ◽  
M. V. Kaminski ◽  
D. B. A. Silk

1. A double lumen jejunal perfusion technique has been used in man to study the effect of peptide chain length on absorption of amino acid nitrogen from two partial enzymic hydrolysates of lactalbumin. 2. Copper-chelation chromatography showed that one lactalbumin hydrolysate (LH2) contained 98% peptides with a chain length > 4, whilst the other (LH1) contained a more even spread of chain lengths with 55% <4. 3. Absorption of total nitrogen and of 14 amino acid residues occurred to a significantly greater extent from the low molecular weight LH1 than from the higher molecular weight LH2. 4. The results suggest that the pattern of nitrogen and amino acid absorption from partial enzymic hydrolysates of whole protein is markedly influenced by peptide chain length and that brush border peptide hydrolysis has an important rate limiting effect on absorption rates.


1981 ◽  
Vol 199 (1) ◽  
pp. 31-41 ◽  
Author(s):  
K J Wilson ◽  
A Honegger ◽  
R P Stötzel ◽  
G J Hughes

High-pressure (‘performance’) liquid chromatography has been used to investigate the reverse-phase chromatographic behaviour of peptides, ranging in length from 2 to 65 amino acid residues, which have originated from primary-sequence determinations or solution/solid-phase syntheses. By using a pyridine/formate-pyridine/acetate/propan-1-ol buffer system, as previously described [Hughes, Winterhalter & Wilson (1979) FEBS Lett. 108, 81-86], the influence of various experimental parameters were examined. (a) Peptide retention was observed to be temperature-independent between 25 and 55 degrees C. (b) The dependence of chromatographic retention on pH decreases with increasing peptide hydrophobicity. (c) Chromatographic results from C8- and C18-chain-length, as well as from 5 micrometers- and 10 micrometers-particle-size, supports were comparable. (d) The hydrophobic strength of the organic solvent in the mobile phase was observed to decrease: propan-1-ol approximately equal to propan-2-ol greater than acetonitrile much greater than methanol. (e) When gradient rates (% of buffer B/unit time) were systematically decreased, peptide retention decreased in a hyperbolic manner. Comparisons of the peptides chromatographed with respect to their measured retention properties and calculated hydrophobicities were performed by computer analysis. Deviation of peptide chromatographic behaviour was observed to be essentially independent of hydrophobicity, chain length and charge. On the basis of the measured retention properties of the chromatographed peptides, hydrophobic constants for the various amino acid side chains were determined and compared with similar constants available from the literature.


Author(s):  
SHEAU WEI CHIONG ◽  
CHEAN HUI NG ◽  
KHOZIRAH SHAARI

Objective: The purpose of this study was to evaluate the LOX inhibitory activity, and predict the drug likeness properties of designed diacyl derivatives of phloroglucinol, using in silico method. Methods: The designed derivatives were subjected to molecular docking using AUTODOCK while the receptor used in this study was built from SWISS MODEL. Drug likeness properties of the derivatives were calculated by online programs i.e. MOLINSPIRATION and PreADMET. Results: Molecular docking study revealed that designed tHGA derivative with four-carbon chain length exhibited the best binding affinity with the docking scores of -7.26kcal/mol. Three types of binding interactions were observed between the derivatives and the receptor site i.e H-bonding, hydrophobic and Van der Waals interactions. The important amino acid residues involved in H-bonding were Gln495 and Gln697, while other amino acid residues, such as Leu754 and Ile 553, were involved in the Van der Waals interaction. The designed tHGA derivatives were mainly stabilized through hydrophobic interactions with His499, His504, Ile538, Phe557 and Val750. In silico physicochemical calculations predicted that all the designed derivatives passed the Lipinski’s Rule of 5, and have good human intestinal absorption property (HIA>70%). Further, all the designed derivatives showed moderate central nervous system absorption (0.6<BBB<2.0), except for the derivative with a longer (5-Cs) chain length. Conclusion: The findings of the present study suggested that changing the acyl and geranyl side chains of the natural product molecule, tHGA, into two acyl bearing side chains, will improve its pharmacodynamic and pharmacokinetic profiles.


1987 ◽  
Vol 57 (01) ◽  
pp. 017-019 ◽  
Author(s):  
Magda M W Ulrich ◽  
Berry A M Soute ◽  
L Johan M van Haarlem ◽  
Cees Vermeer

SummaryDecarboxylated osteocalcins were prepared and purified from bovine, chicken, human and monkey bones and assayed for their ability to serve as a substrate for vitamin K-dependent carboxylase from bovine liver. Substantial differences were observed, especially between bovine and monkey d-osteocalcin. Since these substrates differ only in their amino acid residues 3 and 4, it seems that these residues play a role in the recognition of a substrate by hepatic carboxylase.


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