Articles by Swarna S. Ramaswamy in JoVE
발광 공명 에너지는 포유 동물 세포에 표현 막 단백질의 구조 변화를 연구에 전송 Drew M. Dolino1, Swarna S. Ramaswamy1, Vasanthi Jayaraman1 1Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston 우리는 여기에 우리가 기증자와 수용체 형광 사이트 사이의 단백질 분해 효소 절단 부위를 소개 향상된 발광 공명 에너지 전달 (LRET) 방법을 설명합니다. 이 변형은 우리가 단백질의 정제없이 막 단백질의 연구를 허용 관심 막 단백질에서 발생하는 특정 LRET 신호를 획득 할 수있다.
Other articles by Swarna S. Ramaswamy on PubMed
Proton-mediated Conformational Changes in an Acid-sensing Ion Channel The Journal of Biological Chemistry. Dec, 2013 | Pubmed ID: 24196950 Acid-sensing ion channels are cation channels activated by external protons and play roles in nociception, synaptic transmission, and the physiopathology of ischemic stroke. Using luminescence resonance energy transfer (LRET), we show that upon proton binding, there is a conformational change that increases LRET efficiency between the probes at the thumb and finger subdomains in the extracellular domain of acid-sensing ion channels. Additionally, we show that this conformational change is lost upon mutating Asp-238, Glu-239, and Asp-260, which line the finger domains, to alanines. Electrophysiological studies showed that the single mutant D260A shifted the EC50 by 0.2 pH units, the double mutant D238A/E239A shifted the EC50 by 2.5 pH units, and the triple mutant D238A/E239A/D260A exhibited no response to protons despite surface expression. The LRET experiments on D238A/E239A/D260A showed no changes in LRET efficiency upon reduction in pH from 8 to 6. The LRET and electrophysiological studies thus suggest that the three carboxylates, two of which are involved in carboxyl/carboxylate interactions, are essential for proton-induced conformational changes in the extracellular domain, which in turn are necessary for receptor activation.