A Toxic Metal “Sponge”

A Novel Technology For Water Remediation…

California State University, Long Beach

Phuc Nguyen

Acey Lab

1

2015 ACS Southern California Undergraduate Research conference, UC San Diego

OUTLINE

The ProblemMetallothionein OverviewExperiments:•Purification•Metal Binding Properties•Metal Recovery technology

Conclusion

2

3

THE PROBLEM

Wastewater Containing Toxic Metals

Lead | Mercury | Arsenic

4

THE ANSWER: METALLOTHIONEIN (MT)

• Low Molecular Weight.• Cysteine rich.• Selectively Binds Toxic/Precious Metals

Hg, Pb, As, U Au, Ag, Pt, Pd

• High Affinity: 4 x 10-14 M-1 for Pb• Active At Extreme Conditions

Temperature - 100oC pH - 4 to 10

5

EXPRESSION AND PURIFICATION OF RECOMBINANT MTMT Gene Cloned into pET 11a

Recombinant MT Expressed in BL-21 E.coli

Sonication

G-50 Sephadex Gel Filtration

Mono Q Anion Exchange

Superdex Gel Filtration

6

SDS-PAGE ANALYSIS OF PURIFIED MT

MT6.5 KDa

Standards

26.6 KDa

16.9 KDa

7

METAL BINDING ACTIVITY

Free-metal

MT-bound metal

8

METAL BINDING ACTIVITY

9

METAL BINDING IN ACETONE

10

TECHNOLOGY FOR METAL REMOVAL

US Patent Number 7,273,962.

11

METAL RECOVERY FROM SEA WATER

585 CPM 109Cd

4,612 CPM 109Cd

12

CONCLUSION

•Recombinant MT is Expressed and Purified•MT binds a Number of Toxic/ Precious Metals •Active in 30% Acetone•Metal Binding Effective In High Salt

13

Dr. Roger Acey

Dr. Katherine Kantardjieff

Paul Madera

Brent Wilkinson

Aaron Ong

Hieu Nguyen

ACKNOWLEDGEMENT