SMT - Characterizing Lambda Phage Binding to Maltoporin


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PHILIP A. GURNEV

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Characterizing Lambda Phage Binding to Maltoporin

Maltoporin is both a sugar-specific porin and an outer membrane receptor for Lambda phage in gram-negative bacteria. By reconstituting a single Maltoporin channel into a planar lipid bilayer we observe the process of docking of a single phage particle to Maltoporin as a sharp change in the channel transport properties [ Manuscript in preparation].

A: Incorporated into a planar lipid bilayer Maltoporin produces a permanently open trimeric channel. B: Addition of sugar (maltohexaose) induces fluctuations in the channel current that reflect an interaction of single sugar molecules with internal binding sites of the three pores of Maltoporin. Phage is added simultaneously with the sugar.

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Collaborators:

	Amos B. Oppenheim
	Mathias Winterhalter

A: Incorporated into a planar lipid bilayer Maltoporin produces a permanently open trimeric channel.

B: Addition of sugar (maltohexaose) induces fluctuations in the channel current that reflect an interaction of single sugar molecules with internal binding sites of the three pores of Maltoporin. Phage is added simultaneously with the sugar.

C: When a phage particle docks to a specific site in Maltoporin (arrow), it reduces ion current and obstructs completely the sugar penetration into Maltoporin pores from the side of phage addition.

D: Sugar added from the opposite side of the membrane, however, can reach the sugar-binding sites of the trimer, suggesting that phage docking does not destroy the overall structure of the Maltoporin channel.


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