Ultrasonic absorption in bovine serum albumin(BSA) aqueous solutions(50 g/ℓ) has been measured at 20℃ over the frequency range 0.1∼100MHz in the pH range 1.5∼13.2. Three different techniques were used ; the plano-concave resonator, plano-plano resonator, and Bragg reflection methods. At acid pH's, excess absorption over that at pH 7 was explained by double relaxation. The pH dependences of the relaxation frequency and maximum absorption per wavelength showed that the relaxation at about 200kHz was related to the expansion of molecules and that at 2MHz resulted from the proton transfer reaction of carboxyl group. At alkaline pH's, the excess absorption was explained by trip]e relaxation. The relaxation at about 200kHz was associated with a helix-coil transition, and the two relaxations at 2 and 15MHz were attributed to the proton transfer reactions of phenolic and amino groups, respectively. The rate constants and volume changes associated with these processes were estimated.

소혈청 albumin(BSA) 수용액의 초음파흡수 mechanism을 규명하기 위해 pH 1.5∼13.2에 대해 주파수 0.1∼100MHz의 범위에 걸쳐 초음파 흡수측정을 행하였다. 측정방법은 plano-concave 공명법(0.1∼2MHz). plano-plano 공명법(3∼10MHz)과 Bragg 반사법(12∼100MHz)을 사용하였다. 산측에는 2MHz와 200kH2 부관에 두개의 완화현상이 나타났고 2MHz의 완화현강은 carboxyl group의 proton전이에 의한 것으로, 200kHz는 BSA분자의 팽창에 의한 것임을 알았다. 알카리측에는 200k, 2와 15MHz 부근에 3개의 완화현상이 나타났고 2와 15MHz의 완화현상은 각각 phenolic와 amino group의 proton전이에 의한 것으로, 200kHz의 완화는 helix-coil 전이에 의한 것으로 임을 알았다.

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