ABSTRACT
Photosynthetic reaction center proteins (RC) purified from purple bacterial strains were deposited on graphene layer prepared by liquid phase exfoliation and light-induced resistance change was measured. By measuring the temperature dependence of the resistance change of the bare and RC covered graphene and comparing with the one inactivated by protein unfolding, two effects were possible to separate. One of them is the resistance change due to temperature effect. The other one clearly indicates a possible electric/electronic interaction between the charge flow in the graphene and the light-induced charge pair within the protein, which is, essentially, different in the open (dark, PBPheo) and closed (light, P+BPheo-) states. These results provide useful information for designing hybrid bio-photonic devices which are able to absorb and convert light energy.
ABSTRACT
Changes in the expression of proteins on cancer cell surface are a typical outcome of malignant transformation. Natural killers (NKs) utilize a set of activating and inhibitory receptors that enable them to recognize altered protein expression and then destroy 'stressed' cells such as cancer or virus-infected cells. Major histocompatibility complex class I polypeptide-related sequence A and B (MICA and MICB, respectively) are expressed by various human tumors and can be recognized by activating NK cell receptor NKG2D. However, cancer frequently escapes recognition by NK cells by proteolytic shedding of MICA and MICB proteins. A study carried out by Ferrari de Andrade and colleagues showed that monoclonal antibody targeting the site of proteolytic shedding of MICA and MICB reduced the progression of melanoma in immunocompromised and immune competent mice models by activation of NKG2D. This approach prevented the reduction of essential immunostimulatory ligands (MICA/MICB) and restored NK cell-driven anticancer immunity.
