Effect of pressure upon the fluorescence of various flavodoxins

Journal Article · Tue Nov 01 00:00:00 EST 1977 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00641a020· OSTI ID:5238089

Visser, A J.W.G.; Li, T M; Drickamer, H G; Weber, G

The effects of hydrostatic pressure in the range of 10/sup -3/ to 11 kbar on the fluorescence of flavodoxins from Peptostreptococcus elsdenii, Desulfovibrio vulgaris, Azotobacter vinelandii, and Clostridium MP were investigated. The first three flavoproteins showed under high pressure enhancements of flavin fluorescence of over 50 times resulting from the release of flavin mononucleotide from the protein complex. The Clostridial flavodoxin showed a very much smaller fluorescence change. At pH 7.5 the high-pressure fluorescence changes of the flavodoxins of D. vulgaris and P. elsdenii were not reversed by decompression, but in A. vinelandii the pressure changes were over 80% reversible. At pH 5 over 80% reversibility was restored to the flavodoxins of D. vulgaris and P. elsdenii, although the pressure dependence of the fluorescence changes was very similar in the reversible and irreversible cases. The midpoint pressures in the reversible reactions were 4.7 kbar (D. vulgaris), 8.7 kbar (P. elsdenii), and 10.6 kbar (A. vinelandii) indicating specific differences in the flavin binding regions. Apparent volume changes in these reactions were 65 to 75 mL/mol indicating participation of a large fraction of the protein in the pressure-induced changes. The irreversible changes are not related to protein aggregation and are believed to result from a pressure-dependent covalent modification, not yet characterized, of the flavin binding region of the protein.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 5238089
• Journal Information: Biochemistry; (United States), Vol. 16:22
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AZOTOBACTER
BIOCHEMICAL REACTION KINETICS
BACTERIA
CLOSTRIDIUM
FLUORESCENCE
PRESSURE DEPENDENCE
ISOALLOXAZINES
PROTEINS
HYDROSTATICS
HETEROCYCLIC COMPOUNDS
KINETICS
LUMINESCENCE
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
REACTION KINETICS
550200* - Biochemistry