Single-molecular enzymatic elongation of hyaluronan polymers visualized by high-speed atomic force microscopy.
J Am Chem Soc
; 134(50): 20254-7, 2012 Dec 19.
Article
em En
| MEDLINE
| ID: mdl-23181584
ABSTRACT
Using high-speed scanning atomic force microscopy, we directly observed single-molecular enzymatic elongation of hyaluronan polymer chains at intervals of 10 s on a mica or lipid bilayer surface, on which Pasteurella multocida hyaluronic acid synthase (pmHAS) was immobilized. The reaction was started by the addition of both UDP-glucuronic acid and UDP-N-acetylglucosamine monomers. The average catalytic elongation rate constant (k(cat)) was found to be 1.8 mer s(-1) from one active enzyme physically adsorbed on a mica surface. When pmHAS was immobilized by inserting its hydrophobic tail part into lipid bilayers, most of the enzymes retained their activity, and the k(cat) values were found to be in the range 1-10 mer s(-1) for 29 enzymes (average was k(cat) = 2-4 mer s(-1)). These k(cat) values were lowest level of k(cat) = 1-100 s(-1) obtained in bulk solution by radioisotope methods.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Polímeros
/
Microscopia de Força Atômica
/
Ácido Hialurônico
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Japão