TY - JOUR
T1 - Effect of conformational changes and differences of proteins on frictional properties of poly(vinyl alcohol) hydrogel
AU - Nakashima, Kazuhiro
AU - Sawae, Yoshinori
AU - Murakami, Teruo
N1 - Funding Information:
This study was partly supported by the Grant-in-Aid for Scientific Research (A) nos. 15200037 and 16760112 from Japan Society for the Promotion of Science and no. 15086212 from Ministry of Education, Culture, Sports, Science and Technology.
PY - 2007/10
Y1 - 2007/10
N2 - In this study, albumin or γ-globulin, both of which are included in natural synovial fluid, was used as an additive into lubricants to investigate the ability to reduce the friction for poly(vinyl alcohol) hydrogel in mixed lubrication. It was found from a measurement in circular dichroism that albumin contains a large amount of α-helix structure and γ-globulin contains a large amount of β-sheet structure. The lubricant containing only albumin showed low friction compared to the lubricant containing only γ-globulin. The effect of protein boundary film was clarified by changing lubricant. Albumin kept the friction low after changing from γ-globulin used at initial rubbing, but γ-globulin increased the friction after changing from albumin at initial rubbing. From a sliding distance of 600 m, albumin showed lower friction but γ-globulin showed higher friction. Therefore, in the case of friction decreasing, γ-globulin forms a tight adsorbed layer and subsequently albumin forms a layer with low shearing strength. Hence, it is important to apply the adsorption layer of γ-globulin at the bottom and make a layered structure composed of albumin and γ-globulin to reduce both friction and wear.
AB - In this study, albumin or γ-globulin, both of which are included in natural synovial fluid, was used as an additive into lubricants to investigate the ability to reduce the friction for poly(vinyl alcohol) hydrogel in mixed lubrication. It was found from a measurement in circular dichroism that albumin contains a large amount of α-helix structure and γ-globulin contains a large amount of β-sheet structure. The lubricant containing only albumin showed low friction compared to the lubricant containing only γ-globulin. The effect of protein boundary film was clarified by changing lubricant. Albumin kept the friction low after changing from γ-globulin used at initial rubbing, but γ-globulin increased the friction after changing from albumin at initial rubbing. From a sliding distance of 600 m, albumin showed lower friction but γ-globulin showed higher friction. Therefore, in the case of friction decreasing, γ-globulin forms a tight adsorbed layer and subsequently albumin forms a layer with low shearing strength. Hence, it is important to apply the adsorption layer of γ-globulin at the bottom and make a layered structure composed of albumin and γ-globulin to reduce both friction and wear.
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U2 - 10.1016/j.triboint.2007.02.010
DO - 10.1016/j.triboint.2007.02.010
M3 - Article
AN - SCOPUS:34548210921
SN - 0301-679X
VL - 40
SP - 1423
EP - 1427
JO - Tribology International
JF - Tribology International
IS - 10-12 SPEC. ISS.
ER -