Thymus leukemia (TL) alloantigenic activity was solubilized by papain proteolytic digestion from intact RADA1 tumor cells. If the cells were labeled with amino acids and fucose, the TL alloantigen could be isolated as a doubly labeled glycoprotein fragment by indirect precipitation from the papain digest. This TL glycoprotein fragment was approximately the same mol wt as the papain-digested H-2...

Blood-brain barrier (BBB) P-glycoprotein activity is rapidly reduced by vascular endothelial growth factor (VEGF) acting via Src and by tumor necrosis factor-alpha acting via protein kinase C (PKC)beta1. To probe underlying mechanism(s), we developed an in vivo, immunoblot-based proteinase K (PK) protection assay to assess the changes in the P-glycoprotein content of the BBB's luminal membrane....

We labeled surface glycoproteins of human platelets by the neuraminidase-galactose oxidase/borotritiide and the periodate/borotritiide methods. When labeled platelets were treated with 1-nM thrombin, a minor glycoprotein weighing 68,000-85,000-d was lost from the surface, and a soluble glycoprotein weighing 57,000-68,000-d was found in the supernatant. Treatment of platelets with ADP, collagen,...

Specific antibodies against human alpha1-acid glycoprotein reacted with human lymphocytes, granulocytes, and monocytes. The antigen on the leukocytes is an externally located integral membrane glycoprotein which is made by the cells and has an apparent mol wt of 52,000. It is released from cells in vitro to the culture medium. The mol wt of the soluble fragment is 41,000, which corresponds to t...

BACKGROUND The efflux transporter P-glycoprotein, a member of the adenosine triphosphate-binding cassette superfamily, is a major determinant of the pharmacokinetics and pharmacodynamics of the opioid loperamide, a well-recognized antidiarrheal agent. Animal studies indicate that P-glycoprotein limits morphine entry into the brain. In this study, the authors examined whether other opioids of im...

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19, so understanding its biology and infection mechanisms critical to facing this major medical challenge. SARS-CoV-2 known use spike glycoprotein interact with cell surface as a first step in process. As for other coronaviruses, it likely that next undergoes endocytosis, but whether or not required inf...

The multidrug resistance P-glycoprotein is a transmembrane efflux pump expressed by lymphocytes and is involved in their cytolytic activity. In the present study, we investigated the age-related changes of P-glycoprotein function in normal peripheral blood lymphocytes. Blood samples from 90 normal volunteers (age range, 0 to 86 years) were analyzed. P-glycoprotein function was assessed by the f...

BACKGROUND Neoadjuvant chemotherapy (NACT) is an integral part of multi-modality approach in the management of locally advanced breast cancer. It is vital to predict response to chemotherapy in order to tailor the regime for a particular patient. The prediction would help in avoiding the toxicity induced by an ineffective chemotherapeutic regime in a non-responder and would also help in the pla...

Two monoclonal antibodies-one that blocks ristocetininduced platelet binding of von Willebrand factor to glycoprotein lb and one that blocks adenosine diphosphateinduced binding of fibrinogen to the glycoprotein llb/Illa complex-were used to assess the binding site(s) for von Willebrand factor when platelets are stimulated with thrombin or adenosine diphosphate (ADP). Neither agonist induced bi...

A glycoprotein was isolated from the M-1 acid glycoprotein fraction of human colostrum. It had a molecular weight of 31200 and contained 27% galactose, 21.7% hexosamine, 8.0% fucose and 10.8% sialic acid by weight. The glycoprotein had no absorption maxima in the 240-300nm region, and was virtually free of ABH(O) and M and N blood-group activity. Alkaline borohydride cleavage of the glycoprotei...