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Titolo:
COUPLING OF PROTEIN SURFACE HYDROPHOBICITY CHANGE TO ATP HYDROLYSIS BY MYOSIN MOTOR DOMAIN
Autore:
SUZUKI M; SHIGEMATSU J; FUKUNISHI Y; HARADA Y; YANAGIDA T; KODAMA T;
Indirizzi:
TOHOKU UNIV,DEPT MET,FAC ENGN SENDAI MIYAGI 98077 JAPAN AIST,NATL INST ADV INTERDISCIPLINARY RES,MECH ENGN LAB TSUKUBA IBARAKI 305 JAPAN KYUSHU INST TECHNOL,LAB MOL ENZYMOL IIZUKA FUKUOKA 820 JAPAN RUTGERS STATE UNIV,DEPT CHEM NEW BRUNSWICK NJ 08855 JRDC,ERATO,YANAGIDA BIOMOTRON PROJECT MINO 562 JAPAN OSAKA UNIV,FAC ENGN SCI,DEPT BIOPHYS ENGN TOYONAKA OSAKA 560 JAPAN
Titolo Testata:
Biophysical journal
fascicolo: 1, volume: 72, anno: 1997,
pagine: 18 - 23
SICI:
0006-3495(1997)72:1<18:COPSHC>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
MUSCLE MYOSIN; SUBFRAGMENT-1; SOLVATION; BINDING;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
27
Recensione:
Indirizzi per estratti:
Citazione:
M. Suzuki et al., "COUPLING OF PROTEIN SURFACE HYDROPHOBICITY CHANGE TO ATP HYDROLYSIS BY MYOSIN MOTOR DOMAIN", Biophysical journal, 72(1), 1997, pp. 18-23

Abstract

Dielectric spectroscopy with microwaves in the frequency range between 0.2 and 20 GHz was used to study the hydration of myosin subfragment1 (S1). The data were analyzed by a method recently devised, which can resolve the total amount of water restrained by proteins into two components, one with a rotational relaxation frequency (f(c)) in the gigahertz region (weakly restrained water) and the other with lower f(c) (strongly restrained water), The weight ratio of total restrained water to S1 protein thus obtained (0.35), equivalent to 2100 water molecules per S1 molecule, is not much different from the values (0.3-0.4) for other proteins. The weakly restrained component accounts for about two-thirds of the total restrained water, which is in accord with the number of water molecules estimated from the solvent-accessible surfacearea of alkyl groups on the surface of the atomic model of S1. The number of strongly restrained water molecules coincides with the number of solvent-accessible charged or polar atoms. The dynamic behavior of the S1-restrained water during the ATP hydrolysis was also examined ina time-resolved mode, The result indicates that when S1 changes from the S1 ADP state into the S1 . ADP . P-i state (ADP release followed by ATP binding and cleavage), about 9% of the weakly restrained waters are released, which are restrained again on slow P-i release, By contrast, there is no net mobilization of strongly restrained component, The observed changes in S1 hydration are quantitatively consistent with the accompanying large entropy and heat capacity changes estimated by calorimetry (Kodama, 1985), indicating that the protein surface hydrophobicity change plays a crucial role in the enthalpy-entropy compensation effects observed in the steps of S1 ATP hydrolysis.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/09/20 alle ore 15:09:50