An Equation for the Reconstitution of Membrane Proteins and a Method for Determination of Pore Content in Biological Membranes

L. S. Lagutina, P. K. Sholtz, D. V. Mamaev, and K. F. Sholtz^*

Bakh Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 117071 Russia; fax: (095) 954-2732; E-mail: inbio@glas.apc.org

^* To whom correspondence should be addressed.

Received March 17, 1998; Revision received May 15, 1998

---

The dependence between specific trapped volume of liposomes (W) and protein concentration (p) is proposed to be used for quantitative pore determination in biological membranes via pore reconstitution into liposomes. This dependence is described by the following equation:

p = -p_e · ln W/W₀,

where W₀ is initial trapped volume of liposomes and p_e is an equivalent protein concentration at which molar concentrations of pores and liposomes become equal. Experimentally determined equivalent protein concentration p_e is the basis of the method. This method also permits determination of molar mass of pore-forming complexes provided that preparations contain purified complex.

---

KEY WORDS: porins, biological membranes, equation for pore participation, quantitation of pores

---