Assembly-controlled biocompatible interface on a microchip: Strategy to highly efficient proteolysis

作者：Liu, Yun; Zhong, Wei; Meng, Sheng; Kong, Jilie; Lu, Haojie; Yang, Pengyuan; Girault, Hubert H.; Liu, Baohong^*

来源：Chemistry - A European Journal, 2006, 12(25): 6585-6591.

DOI：10.1002/chem.200501622

• interfaces
• layer-by-layer assembly
• microchip reactors
• proteomics
• trypsin

A biocompatible interface was constructed on a microchip by using the layer-by-layer (LBL) assembly of charged polysaccharides incorporating proteases for highly efficient proteolysis. The controlled assembly of natural polyelectrolytes and the enzyme-adsorption step were monitored by using a quartz-crystal microbalance and atomic force microscopy (AFM). Such a multilayer-assembled membrane provides a biocompatible interconnected network with high enzyme-loading capacity. The maximum digestion rate of the adsorbed trypsin in a microchannel was significantly accelerated to 1600 mm min(-1) mu g(-1), compared with the tryptic digestion in solution. Based on the Langmuir isotherm model, the thermodynamic constant of adsorption K was calculated to be 1.6 x 10(5) M-1 and the maximum adsorption loading Gamma(max) was 3.6 x 10(-6) mol m(-2), 30 times more than a monolayer of trypsin on the native surface. The tunable interface containing trypsin was employed to construct a microchip reactor for digestion of femtomoles of proteins and the produced peptides were analyzed by MALDI-TOF mass spectroscopy. The efficient on-chip proteolysis was obtained within a few seconds, and the identification of biological samples was feasible.

• 出版日期2006-8-25
• 单位复旦大学