Biophysical characterization of a binding site for TLQP-21, a naturally occurring peptide which induces resistance to obesity.
Biochim Biophys Acta
; 1828(2): 455-60, 2013 Feb.
Article
em En
| MEDLINE
| ID: mdl-23122777
ABSTRACT
Recently, we demonstrated that TLQP-21 triggers lipolysis and induces resistance to obesity by reducing fat accumulation [1]. TLQP-21 is a 21 amino acid peptide cleavage product of the neuroprotein VGF and was first identified in rat brain. Although TLQP-21 biological activity and its molecular signaling is under active investigation, a receptor for TLQP-21 has not yet been characterized. We now demonstrate that TLQP-21 stimulates intracellular calcium mobilization in CHO cells. Furthermore, using Atomic Force Microscopy (AFM), we also provide evidence of TLQP-21 binding-site characteristics in CHO cells. AFM was used in force mapping mode equipped with a cantilever suitably functionalized with TLQP-21. Attraction of this functionalized probe to the cell surface was specific and consistent with the biological activity of TLQP-21; by contrast, there was no attraction of a probe functionalized with biologically inactive analogues. We detected interaction of the peptide with the binding-site by scanning the cell surface with the cantilever tip. The attractive force between TLQP-21 and its binding site was measured, statistically analyzed and quantified at approximately 40 pN on average, indicating a single class of binding sites. Furthermore we observed that the distribution of these binding sites on the surface was relatively uniform.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Peptídeos
/
Biofísica
/
Obesidade
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article