SAXSMoW 2.0: Online calculator of the molecular weight of proteins in dilute solution from experimental SAXS data measured on a relative scale

Autor(es)

Piiadov, Vassili ^[1] ; de Araujo, Evandro Ares ^[1] ; Oliveira Neto, Mario ^[2] ; Craievich, Aldo Felix ^[3] ; Polikarpov, Igor ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Phys Sao Carlos, Sao Carlos, SP - Brazil

^[2] Univ Estadual Paulista, Inst Biosci, Botucatu, SP - Brazil

^[3] Univ Sao Paulo, Inst Phys, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Protein Science; v. 28, n. 2, p. 454-463, FEB 2019.
• Citações Web of Science: 7

Resumo

Knowledge of molecular weight, oligomeric states, and quaternary arrangements of proteins in solution is fundamental for understanding their molecular functions and activities. We describe here a program SAXSMoW 2.0 for robust and quick determination of molecular weight and oligomeric state of proteins in dilute solution, starting from a single experimental small-angle scattering intensity curve, I(q), measured on a relative scale. The first version of this calculator has been widely used during the last decade and applied to analyze experimental SAXS data of many proteins and protein complexes. SAXSMoW 2.0 exhibits new features which allow for the direct input of experimental intensity curves and also automatic modes for quick determinations of the radius of gyration, volume, and molecular weight. The new program was extensively tested by applying it to many experimental SAXS curves downloaded from the open databases, corresponding to proteins with different shapes and molecular weights ranging from similar to 10 kDa up to about similar to 500 kDa and different shapes from globular to elongated. These tests reveal that the use of SAXSMoW 2.0 allows for determinations of molecular weights of proteins in dilute solution with a median discrepancy of about 12% for globular proteins. In case of elongated molecules, discrepancy value can be significantly higher. Our tests show discrepancies of approximately 21% for the proteins with molecular shape aspect ratios up to 18. (AU)

• Processo FAPESP: 15/13684-0 - Estudos estruturais e funcionais de enzimas que participam na síntese e degradação de carboidratos complexos
• Beneficiário: Igor Polikarpov
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/00769-5 - Estudos estruturais de hidrolases de glicosídeos em solução usando técnicas de espalhamento a baixo ângulo (SAS)
• Beneficiário: Vasilii Piiadov
• Linha de fomento: Bolsas no Brasil - Doutorado Direto