
Biotechnology and Applied Biochemistry (1999) 29, (2530) (Printed in Great Britain)
Solvent effect on kinetics of appearance of haemorphins in the course of peptic hydrolysis of bovine haemoglobin
Brigitte Lignot, Renato Froidevaux, Naima Nedjar-Arroume1 and Didier Guillochon
Laboratoire de Technologie des Substances Naturelles, IUT 'A' Lille 1, BP 179, 59653 Villeneuve d'Ascq Cédex, France
Abbreviations used: DHc, corrected degree of hydrolysis; MALDIMS,
matrix-assisted laser desorption ionization MS.1 To whom
correspondence should be addressed.
The effect of the composition of the solvent on the peptic
hydrolysis of bovine haemoglobin was studied to improve the preparation
of two opioid peptides. Peptic hydrolysis was performed for 24 h at
23 °C in 0.1 M sodium acetate buffer, pH 4.5. A HPLC
method was reported for isolating LVV-haemorphin-7 and VV-haemorphin-7
in one step. The kinetics of appearance of haemorphins was investigated
in the presence of 20% (v/v) ethanol, a stabilizing solvent of haemoglobin
or urea, a denaturant agent. Ethanol improved the yield of VV-haemorphin-7,
whereas urea improved the yield of the two haemorphins. Because the amounts
of haemorphins observed in urea were greater than in ethanol, the denatured
state of haemoglobin is more favourable to obtaining LVV-haemorphin-7 and
W-haemorphin-7. The peptide bonds that give rise to haemorphins would be
more accessible to the pepsin.
Received 27 july 1998; accepted 11 September 1998
Portland Press Ltd © 1999
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