Immobilization of Trypsin onto Silk Fibroin Fiber via Spacer Arms

다국어 초록 (Multilingual Abstract)

Trypsin can be immobilized on silk fibroin fiber (SFF)
by introducing several spacer arms, such as ethylene
diamine (ED), bovine serum albumin (BSA) and silk
sericin (SS). Direct immobilization on silk fiber (SFFGA)
has low activity because of the steric hindrance
between the trypsin and substrate. The introduction of
spacer arms onto SFF-GA can enhance the activity of
trypsin by reducing the steric hindrance. When ED is
used as a spacer arm, the activity of trypsin has
increased but its stability decreased due to the
increased hydrophobicity of SFF. BSA and SS, as a
spacer arm, have better results in both activity and
stability. SFF-BSA shows some decrease in the specific
activity due to improper immobilization. SFF-SS
maintained 90% of its initial activity even after 12 hrs
incubation at 50°C. In the case of repeated hydrolysis
of silk sericin with immobilized trypsin, SFF-GA and
SFF-ED lost 50% of their initial activity right after
first run, whereas SFF-BSA and SFF-SS maintained
80% of their initial activities even after 5 runs. Higher
operational stability is due to increased hydrophilicity
of SFF by introducing hydrophilic spacer arms such as
BSA and SS. The high content of serine in SS increases
the hydrophilicity of SFF resulting the best results
among other spacer arms.

참고문헌 (Reference)

1 "Use of silk fibroin for enzyme membrane. J. Biotech.5" 1987199-207.

2 "Use of dextrans as long and hydrophilicspacer arms to improve the performance of immobilized proteinsacting on macromolecules. Biotech. Bioeng." 60 : 518-523, 1998

3 "Studies on dissolution behaviors and struc-tural characterization of silk sericin" 135-256, 1975

4 "Structure of silk studied withNMR. Prog. Nucl. Mag. Res. Sp." 39 : 301-352, 2001

5 "Sol-gel powders and supported sol-gel polymers for immobilization of lipase in ester synthesis.Enzyme Microb. Technol. 32" 801-811, 2003

6 "Regeneratedsilk fibroin membrane as immobilization matrix for peroxi-dase and fabrication of a sensor for hydrogen peroxide utiliz-ing methylene blue as electron shuttle. Anal. Chim. Acta" 316 : 65-72, 1995

7 "Producing of non-woven silk fabrics and silk felt. Bull. Sericult. Exp. Stat. 134" 281-295, 1988

8 "Preparation of silk nonwoven fabrics by needle punching, thermal bonding and its properties." 41 : 205-210, 1999

9 "Multipoint attachment to a support protects enzymefrom inactivation by organic solvents a-chymotrypsin inaqueous solutions of alcohols and diols. Biotech. Bioeng. 35" 653-659, 1990

10 "Mechanism of glucose oxidase immobilization withsilk fibroin. J. Seric. Sci. Jpn 57" 203-209, 1988

11 "Immobilized enzymes: methods and applications" 200 : 95-126, 1999

12 "Immobilization of enzymes acting on macromolecu- lar substrates; in Immobilization of enzymes and cells. Bick- erstaff, G. F. (ed.)" 261-275, 1997

13 "Immobilization of alkaline phosphate on silk using diazo optimum pHand properties of the conjugates. Biotech. Bioeng. 25" 1423-1434, 1982

14 "Hydrophobic parameters p ofamino acid side chains from the portioning of N-acetyl-amino-acid amides. Eur. J. Med. Chem. 18" 369-375, 1983

15 "Differential binding of IgG and IgA antibodies to antigenic determinants of bovine serum albu- min. Clin. Exp. Immunol" 123 : 387-394, 2001

16 "Amperometricbiosensor for uric acid based on uricase-immobilizedsilk fibroin membrane. Anal. Chim. Acta." 369 : 123-128, 1998

17 "A fibrous-bed biore-actor for continuous production of development endotheliallocus-1 by osteosarcoma cells. J. Biotechnol. 97" 23-39, 2002