MICRO-ARRAY CHIP FOR HIGH THROUGHPUT PROTEIN CRYSTALLOGRAPHY

 

N. Watanabe,a I. Tanaka,a C. Nishijima,b H. Takeuchi,b T. Sumic and T. Isekib

 

aDivision of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan; bChemicals Development Laboratories, Mitsubishi Rayon Co., LTD. Yokohama, Japan; cProduction Technology Center, Mitsubishi Rayon Co., LTD. Hiroshima, Japan (nobuhisa@sci.hokudai.ac.jp)

 

 

Since protein crystallization is influenced by a number of factors, development of a method for high throughput protein crystallization is one of the most important steps for accomplishment of structural genomics. We have been developing a unique device for high throughput screening of protein crystallization condition with nano-volume [1]. The device is micro-array chip utilizing the fiber type DNA chip technology.

In order to hold various precipitant conditions in arrayed hollow fibers on the chip, several kinds of gels are used. We have already fixed types and polymerization conditions of gels for almost all precipitants and wide range of buffer pH. It is possible to make arrayed chip for random conditions such as Crystal Screens of Hampton Research and Wizard Screens of Emerald BioStructures. A property of precipitants in a gel has been confirmed by comparing crystallization results with batch method.

The prototype array has from 12 to 48 different crystallization conditions integrated on a cover glass size chip. Each precipitant solution of 50 nL is kept in a hollow fiber of the arrayed chip separately. One should just put protein solution onto the chip manually with any single auto-pipetter. Protein and the precipitant solutions are mixed in the micro cell on the chip, and crystallization screening will be performed. Only 50 nL for each crystallization condition, total of about 2 to 10 micro-L protein solution, including loss, is required for screening of conditions on the chip.

Text Box: Figure. An arrayed chip of 48 conditions and its magnified view.

Using the chip, we can perform many screening conditions without any robotic systems. Our unique screening procedure will make it possible to set up more than 100 different crystallization conditions within a few minutes.

 


References

1       Watanabe, N., Akita, T., Sumi, T., Takeuchi, H. and Tanaka, I. (2002) Acta Cryst. A58, C94