Spatial specificity of chromophore assisted laser inactivation of protein function

• Published in: Biophysical journal 1992-04, Vol.61 (4), p.956-962
• Main Authors: Linden, K.G., Liao, J.C., Jay, D.G.
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase - radiation effects; Alkaline Phosphatase - antagonists & inhibitors; Analytical, structural and metabolic biochemistry; Animals; Antibodies; beta-Galactosidase - antagonists & inhibitors; Biological and medical sciences; Biophysical Phenomena; Biophysics; Fundamental and applied biological sciences. Psychology; General aspects, investigation methods; Humans; In Vitro Techniques; Lasers; Proteins; Proteins - antagonists & inhibitors; Proteins - immunology; Proteins - radiation effects; Rosaniline Dyes; Serum Albumin, Bovine - antagonists & inhibitors; Staphylococcal Protein A - radiation effects
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1016/S0006-3495(92)81902-1

Chromophore assisted laser inactivation (CALI) is a new technique that selectively inactivates proteins of interest to elucidate their in vivo functions. This method has application to a wide array of biological questions. An understanding of aspects of the mechanism of CALI is required for its judicious application. A critical concern for CALI is its spatial specificity because nonspecific inactivation of neighboring unbound proteins by CALI is a possibility. We show here that CALI is very dependent on the distance between the chromophore and the protein such that there is no significant effect beyond 60 A. CALI using antibodies can inactivate other proteins through a complex but its efficacy decreases approximately fourfold for each intervening protein. These data imply that CALI is spatially specific and damage to neighboring proteins is unlikely.