Observation of phosphorylase kinase and phosphorylase b at solid–liquid interfaces by scanning tunneling microscopy

Autor: Virgil B. Elings, Ronald D. Edstrom, Gil U. Lee, D. Fennell Evans
Rok vydání: 1991
Předmět:
Zdroj: Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. 9:1236
ISSN: 0734-211X
Popis: Enzymes can be immobilized at a solid–liquid interface and observed with a scanning tunneling microscope (STM) using the inherent charge of proteins and an external potential applied to the STM substrate. Phosphorylase kinase, and dimers and oligomers of phosphorylase b have been observed at the interface of aqueous solutions and highly oriented pyrolytic graphite (HOPG). The lateral dimensions of phosphorylase kinase determined by STM at the solid–liquid interface are from 74%–78% of the dimensions determined by STM at the solid–air interface [Biochem. 28, 4939 (1989); Biophys. J. (in press)]. The phosphorylase b lateral dimensions of both enzymes are between 1.9 and 2.5 nm greater than the dimensions determined by x‐ray crystallography. The vertical dimensions determined by STM at the solid–liquid and solid–air interfaces are in reasonable agreement with each other. Mixtures of the two enzymes show aggregates in which the complexes of the two enzymes are identifiable. This technique will make it possibl...
Databáze: OpenAIRE