Sayari_2005_FEBS.Lett_579_976

Reference

Title : N-terminal peptide of Rhizopus oryzae lipase is important for its catalytic properties - Sayari_2005_FEBS.Lett_579_976
Author(s) : Sayari A , Frikha F , Miled N , Mtibaa H , Ben Ali Y , Verger R , Gargouri Y
Ref : FEBS Letters , 579 :976 , 2005
Abstract :

In a culture medium, the Rhizopus oryzae strain produces only one form of lipase, ROL32. When the concentrated culture medium was stored at 0 degrees C during several months or kept at 6 degrees C during a few days, we noticed the appearance of a second shorter form of ROL32 lacking its N-terminal 28 amino acid (ROL29). ROL29 was purified to homogeneity and its 21 N-terminal amino acid residues were found to be identical to the 29-49 sequence of ROL32. The cleavage of the N-terminal peptide reduced the specific activity of ROL29 by 50% using either triolein or tributyrin as substrates. In order to explain this decrease of the specific activity of ROL29, we measured its critical surface pressure of penetration into phosphatidyl choline from egg yolk films which was found to be 10 mN/m, in contrast to a value of 23 mN/m found in ROL32. A kinetic study on the surface pressure dependency, stereoselectivity and regioselectivity of ROL29 was performed using the three dicaprin isomers spread as monomolecular films at the air-water interface. Our results showed that in contrast to ROL32, ROL29 presented a preference for the distal ester groups of one diglyceride isomer (1,3-sn-dicaprin). Furthermore, ROL32 was markedly more stereoselective than ROL29 for the sn-3 position of the 2,3-sn-enantiomer of dicaprin. A structural explanation of the enhanced penetration capacity as well as the catalytic activity of ROL32 was proposed by molecular modeling. We concluded that the N-terminal peptide of ROL32 can play an important role in the specific activity, the regioselectivity, the stereoselectivity and the binding of the enzyme to its substrate.

PubMedSearch : Sayari_2005_FEBS.Lett_579_976
PubMedID: 15710378
Gene_locus related to this paper: rhidl-lipas

Related information

Gene_locus rhidl-lipas

Citations formats

Sayari A, Frikha F, Miled N, Mtibaa H, Ben Ali Y, Verger R, Gargouri Y (2005)
N-terminal peptide of Rhizopus oryzae lipase is important for its catalytic properties
FEBS Letters 579 :976

Sayari A, Frikha F, Miled N, Mtibaa H, Ben Ali Y, Verger R, Gargouri Y (2005)
FEBS Letters 579 :976