Primary quantum yield and volume change of phytochrome-A phototransformation determined by laser-induced optoacoustic spectroscopy

被引：28

作者：

Gensch, T ^{[1
]}

Churio, MS ^{[1
]}

Braslavsky, SE ^{[1
]}

Schaffner, K ^{[1
]}

机构：

[1] MAX PLANCK INST STRAHLENCHEM,D-45413 MULHEIM,GERMANY

来源：

PHOTOCHEMISTRY AND PHOTOBIOLOGY | 1996年 / 63卷 / 06期

关键词：

D O I：

10.1111/j.1751-1097.1996.tb09621.x

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The primary quantum yield, phi(I700), for the photoconversion of the red-absorbing form of phytochrome, P-r, to the set of primary intermediates, I-700(i), was redetermined by laser-induced optoacoustic spectroscopy at very low excitation laser fluences. The phi(I700) value obtained is in the range of phi(Pfr) reported for the complete phototransformation P-r --> P-fr (J. M. Kelly and C. Lagarias, 1985, Biochemistry 24, 6003-6010). An energy level of ca 150 kJ/mol was found for the intermediates I-700(i), i.e. ca 85% of the 0-0 level of P-r. Furthermore, a molecular expansion of 7 mL/mol (equivalent to 11 Angstrom(3)/molecule) was determined for the P-r --> I-700(i) transformation. It reflects the protein reorganization induced by the geometrical photoisomerization of the chromophore, which results in changes of bonding interactions, in particular between the chromophore and its protein surrounding.

引用

页码：719 / 725

页数：7

共 43 条

[1] LASER FLASH-PHOTOLYSIS OF 124-KILODALTON OAT PHYTOCHROME IN H2O AND D2O SOLUTIONS - FORMATION AND DECAY OF THE I700 INTERMEDIATES [J].