Roussel, A., Canaan, S., Egloff, M. P., Riviere, M., Dupuis, L., Verger, R., Cambillau, C., J.Biol.Chem. 274, 16995 (1999)

Some test stuff.

Color protein using a link.

Test of a simple button. Make pretty.

Test of a toggle button. Color protein yellow

Presentation by Xiaoqing Liu, Department of Chemistry, University of Massachusetts. December 6, 2004.

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Human gastric lipase (HGL) is an enzyme secreted by human stomach, which catalyzes the hydrolysis of triglyceride. It is stable and keeps activity in acidic environment. The structure of recombinant HGL (rHGL) has been obtained at 3A resolution by X-ray diffraction. The asymmetric unit of rHGL crystal contains two protein molecules, so the resulting crystal of rHGL is a dimer.

is consisted of a (residues 9-183, 309-379) and a (residues 184-308). The core domain contains an 8-strand sheet and helices around. It is a with . The is located on the top of the core domain and it is a typical catalytic triad (Ser 153, Asn 324 and His 353). Gln 154 and Leu 67 form for the catalytic reaction. In this region, there is a sequence motif, , which refers to the particular function of hydrolysis of ester.

The active site is covered by the cap domain. In this area, a is proposed for better understanding the interaction between lipid substrates and HGL. , the active site can be clearly seen. When the lid is open, substrates can come into the active site and take reaction there. can interact with . can be seen as hinge. This protein also contains a .

Because of the limited space around the active site and steric hindrance, not all the three ester bonds can enter the active site. That's why HGL shows a preference for the sn-3 position of triglyceride.