Human bile salt-dependent lipase efficiency on medium-chain acyl-containing substrates: control by sodium taurocholate
H Fontbonne, L Brisson, A Vérine… - The journal of …, 2011 - academic.oup.com
H Fontbonne, L Brisson, A Vérine, A Puigserver, D Lombardo, EH Ajandouz
The journal of biochemistry, 2011•academic.oup.comBile salt-dependent lipase was purified to homogeneity from lyophilized human milk and
used to screen the influence of the acyl chain length (2–16 carbon atoms) on the kinetic
constants k cat and K m of the hydrolysis of para-nitrophenyl (pnp) ester substrates in the
presence or absence of sodium taurocholate (NaTC: 0.02–20 mM). The highest k cat value
(∼ 3,500 s− 1) was obtained with pnpC8 as substrate, whereas the lowest K m (< 10 µM)
was that recorded with pnpC10. In the absence of NaTC, the maximal catalytic efficiency (k …
used to screen the influence of the acyl chain length (2–16 carbon atoms) on the kinetic
constants k cat and K m of the hydrolysis of para-nitrophenyl (pnp) ester substrates in the
presence or absence of sodium taurocholate (NaTC: 0.02–20 mM). The highest k cat value
(∼ 3,500 s− 1) was obtained with pnpC8 as substrate, whereas the lowest K m (< 10 µM)
was that recorded with pnpC10. In the absence of NaTC, the maximal catalytic efficiency (k …
Abstract
Bile salt-dependent lipase was purified to homogeneity from lyophilized human milk and used to screen the influence of the acyl chain length (2–16 carbon atoms) on the kinetic constants kcat and Km of the hydrolysis of para-nitrophenyl (pnp) ester substrates in the presence or absence of sodium taurocholate (NaTC: 0.02–20 mM). The highest kcat value (∼3,500 s−1) was obtained with pnpC8 as substrate, whereas the lowest Km (<10 µM) was that recorded with pnpC10. In the absence of NaTC, the maximal catalytic efficiency (kcat/Km) was obtained with pnpC8, while in the presence of NaTC kcat/Km was maximal with pnpC8, pnpC10 or pnpC12. The bile salt activated the enzyme in two successive saturation phases occurring at a micromolar and a millimolar concentration range, respectively. The present data emphasize the suitability of this enzyme for the hydrolysis of medium-chain acyl-containing substrates and throw additional light on how BSDL is activated by NaTC.
Oxford University Press