University of Maryland Biotechnology Institute

About: University of Maryland Biotechnology Institute is a based out in . It is known for research contribution in the topics: Gene & Population. The organization has 1565 authors who have published 2458 publications receiving 171434 citations. The organization is also known as: UMBI.

Functional studies of crustacean hyperglycemic hormones (CHHs) of the blue crab, Callinectes sapidus - the expression and release of CHH in eyestalk and pericardial organ in response to environmental stress.

Abstract: The rapid increase in the number of putative cDNA sequences encoding crustacean hyperglycemic hormone (CHH) family in various tissues [either from the eyestalk (ES) or elsewhere] underscores a need to identify the corresponding neuropeptides in relevant tissues. Moreover, the presence of provided structural CHH implies the level of the complexity of physiological regulation in crustaceans. Much less is known of the functions of non-ES CHH than of those of its counterpart present in ESs. In the blue crab, Callinectes sapidus, we know little of CHH involvement in response to the stressful conditions that naturally occur in Chesapeake Bay. We have identified two isoforms of CHH neuropeptide in the sinus gland of the ES and isolated a full-length cDNA encoding CHH from the pericardial organ (PO). The functions of ES-CHH and PO-CHH in this species were studied with regard to expression and release in response to stressful episodes: hypoxia, emersion, and temperatures. Animals exposed to hypoxic conditions responded with concomitant release of both CHHs. In contrast, the mRNA transcripts encoding two CHHs were differentially regulated: PO-CHH increased, whereas ES-CHH decreased. This result suggests a possible differential regulation of transcription of these CHHs.

Structure of a lamprey variable lymphocyte receptor in complex with a protein antigen.

Abstract: Variable lymphocyte receptors (VLRs) are leucine-rich repeat proteins that mediate adaptive immunity in jawless vertebrates. VLRs are fundamentally different from the antibodies of jawed vertebrates, which consist of immunoglobulin (Ig) domains. We determined the structure of an anti-hen egg white lysozyme (HEL) VLR, isolated by yeast display, bound to HEL. The VLR, whose affinity resembles that of IgM antibodies, uses nearly all its concave surface to bind the protein, in addition to a loop that penetrates into the enzyme active site. The VLR-HEL structure combined with sequence analysis revealed an almost perfect match between ligand-contacting positions and positions with highest sequence diversity. Thus, it is likely that we have defined the generalized antigen-binding site of VLRs. We further demonstrated that VLRs can be affinity-matured by 13-fold to affinities as high as those of IgG antibodies, making VLRs potential alternatives to antibodies for biotechnology applications.

Host-Guest Complexes with Protein-Ligand-Like Affinities: Computational Analysis and Design

Abstract: It has recently been discovered that guests combining a nonpolar core with cationic substituents bind cucurbit[7]uril (CB[7]) in water with ultrahigh affinities. The present study uses the Mining Minima algorithm to study the physics of these extraordinary associations and to computationally test a new series of CB[7] ligands designed to bind with similarly high affinity. The calculations reproduce key experimental observations regarding the affinities of ferrocene-based guests with CB[7] and β-cyclodextrin and provide a coherent view of the roles of electrostatics and configurational entropy as determinants of affinity in these systems. The newly designed series of compounds is based on a bicyclo[2.2.2]octane core, which is similar in size and polarity to the ferrocene core of the existing series. Mining Minima predicts that these new compounds will, like the ferrocenes, bind CB[7] with extremely high affinities.

Phylogeny and Biogeography of Hawkmoths (Lepidoptera: Sphingidae): Evidence from Five Nuclear Genes

Abstract: Background: The 1400 species of hawkmoths (Lepidoptera: Sphingidae) comprise one of most conspicuous and wellstudied groups of insects, and provide model systems for diverse biological disciplines. However, a robust phylogenetic framework for the family is currently lacking. Morphology is unable to confidently determine relationships among most groups. As a major step toward understanding relationships of this model group, we have undertaken the first large-scale molecular phylogenetic analysis of hawkmoths representing all subfamilies, tribes and subtribes. Methodology/Principal Findings: The data set consisted of 131 sphingid species and 6793 bp of sequence from five protein-coding nuclear genes. Maximum likelihood and parsimony analyses provided strong support for more than twothirds of all nodes, including strong signal for or against nearly all of the fifteen current subfamily, tribal and sub-tribal groupings. Monophyly was strongly supported for some of these, including Macroglossinae, Sphinginae, Acherontiini, Ambulycini, Philampelini, Choerocampina, and Hemarina. Other groupings proved para- or polyphyletic, and will need significant redefinition; these include Smerinthinae, Smerinthini, Sphingini, Sphingulini, Dilophonotini, Dilophonotina, Macroglossini, and Macroglossina. The basal divergence, strongly supported, is between Macroglossinae and Smerinthinae+Sphinginae. All genes contribute significantly to the signal from the combined data set, and there is little conflict between genes. Ancestral state reconstruction reveals multiple separate origins of New World and Old World radiations. Conclusions/Significance: Our study provides the first comprehensive phylogeny of one of the most conspicuous and wellstudied insects. The molecular phylogeny challenges current concepts of Sphingidae based on morphology, and provides a foundation for a new classification. While there are multiple independent origins of New World and Old World radiations, we conclude that broad-scale geographic distribution in hawkmoths is more phylogenetically conserved than previously postulated.

Pathogenic Vibrio Species in the Marine and Estuarine Environment

Abstract: The genus Vibrio includes more than 30 species, at least 12 of which are pathogenic to humans and/or have been associated with foodborne diseases (Chakraborty et al., 1997). Among these species, Vibrio cholerae, serogroups O1 and O139, are the most important, since they are associated with epidemic and pandemic diarrhea outbreaks in many parts of the world (Centers for Disease Control and Prevention, 1995; Kaper et al., 1995). However, other species of vibrios capable of causing diarrheal disease in humans have received greater attention in the last decade. These include Vibrio parahaemolyticus, a leading cause of foodborne disease outbreaks in Japan and Korea (Lee et al., 2001), Vibrio vulnificus, Vibrio alginolyticus, Vibrio damsela, Vibrio fluvialis, Vibrio furnissii, Vibrio hollisae, Vibrio metschnikovii, and Vibrio mimicus (Altekruse et al., 2000; Hoi et al., 1997). In the USA, Vibrio species have been estimated to be the cause of about 8000 illnesses annually (Mead et al., 1999). Vibrios can be classified as either halophilic or nonhalophilic, depending on their requirement for NaCl for optimal growth (Thompson et al., 2004). They are free-living bacteria in the aquatic environment throughout the world. They tend to be more common in warmer waters, notably when temperatures rise above 17 ◦C and, depending on the species, they tolerate a wide range of salinities (Wright et al., 1996). Given their abundance in water, Vibrio species are also commonly isolated from fish and shellfish, with 100-fold higher concentration in filter-feeding shellfish, such as oysters, than in the surrounding water (Wright et al., 1996). During the warm summer months, virtually 100% of oysters can carry V. vulnificus and/or V. parahaemolyticus (Cook et al., 2002b; Motes et al., 1998; Wright et al., 1996). “Epidemic” strains of V. cholerae, which carry specific virulence genes, cause the disease “cholera,” while “nonepidemic” strains are mainly associated with septicemia, gastroenteritis, and wound infections (Levine & Griffin, 1993). However, morbidity due to nonepidemic strains is relatively low, and, in some instances, it is unclear whether isolation of the organism