Enzymatic activity of albumin shown by coelenterazine chemiluminescence.

Bioluminescence, the emission of light from live organisms, occurs in 18 phyla and is the major communication system in the deep sea. It has appeared independently many times during evolution but its origins remain unknown. Coelenterazine bioluminescence discovered in luminous jellyfish is the most common chemistry causing bioluminescence in the sea, occurring in seven phyla. Sequence similarities between coelenterazine luciferases and photoproteins from different phyla are poor (often < 5%). The aim of this study was to examine albumin that binds organic substances as a coelenterazine luciferase to test the hypothesis that the evolutionary origin of a bioluminescent protein was the result of the formation of a solvent cage containing just a few key amino acids. The results show for the first time that bovine and human albumin catalysed coelenterazine chemiluminescence consistent with a mono-oxygenase, whereas gelatin and haemoglobin, an oxygen carrier, had very weak activity. Insulin also catalysed coelenterazine chemiluminescence and was increased by Zn(2+). Albumin chemiluminescence was heat denaturable, exhibited saturable substrate characteristics and was inhibited by cations that bound these proteins and by drugs that bind to human albumin drug site I. Molecular modelling confirmed the coelenterazine binding site and identified four basic amino acids: lys195, arg222, his242 and arg257, potentially important in binding and catalysis similar to naturally occurring coelenterazine bioluminescent proteins. These results support the 'solvent cage' hypothesis for the evolutionary origin of enzymatic coelenterazine bioluminescent proteins. They also have important consequences in diseases such as diabetes, gut disorders and food intolerance where a mono-oxygenase could affect cell surface proteins.

Implementation of the care coordinator role: a grounded theory approach.

The purpose of this study was to explore the process of implementing a new care coordinator role on a medical-surgical unit. Qualitative data were collected from employees and patients during a 3-month period; data analysis occurred concurrently. Using the constant comparative method, a grounded theory was developed to explain the initial process of implementation of the clinical nurse III (CNIII) role. The basic social psychological problem associated with implementation was role ambiguity. The basic social psychological process used to resolve this problem was "making the role of the CNIII". Making the role involves the following four strategies, which may occur simultaneously: communicating the vision, gaining new knowledge, accessing resources, and defining boundaries. Communicating the vision refers to efforts to articulate the role before and during the implementation process. Gaining new knowledge includes participating in educational workshops and acquiring new skills. Accessing resources refers to development of new relationships and acquisition of office space and equipment. Defining boundaries includes determining the scope of responsibilities and differentiating the role from other roles. This theory may be useful to researchers, educators, and administrators interested in role implementation.