The Old and the New: Discovery Proteomics Identifies Putative Novel Seminal Fluid Proteins in Drosophila.

Seminal fluid proteins (SFPs), the nonsperm component of male ejaculates produced by male accessory glands, are viewed as central mediators of reproductive fitness. SFPs effect both male and female post-mating functions and show molecular signatures of rapid adaptive evolution. Although , is the dominant insect model for understanding SFP evolution, understanding of SFP evolutionary causes and consequences require additional comparative analyses of close and distantly related taxa.

Identification and characterization of the zebra finch (Taeniopygia guttata) sperm proteome.

Spermatozoa exhibit remarkable variability in size, shape, and performance. Our understanding of the molecular basis of this variation, however, is limited, especially in avian taxa. The zebra finch (Taeniopygia guttata) is a model organism in the study of avian sperm biology and sperm competition.

Sperm Proteome Maturation in the Mouse Epididymis.

In mammals, transit through the epididymis, which involves the acquisition, loss and modification of proteins, is required to confer motility and fertilization competency to sperm. The overall dynamics of maturation is poorly understood, and a systems level understanding of the complex maturation process will provide valuable new information about changes occurring during epididymal transport. We report the proteomes of sperm collected from the caput, corpus and cauda segments of the mouse epididymis, identifying 1536, 1720 and 1234 proteins respectively.

Structural insights into the evolution of a non-biological protein: importance of surface residues in protein fold optimization.

Phylogenetic profiling of amino acid substitution patterns in proteins has led many to conclude that most structural information is carried by interior core residues that are solvent inaccessible. This conclusion is based on the observation that buried residues generally tolerate only conserved sequence changes, while surface residues allow more diverse chemical substitutions. This notion is now changing as it has become apparent that both core and surface residues play important roles in protein folding and stability.

Oxidative chemistry in the GFP active site leads to covalent cross-linking of a modified leucine side chain with a histidine imidazole: implications for the mechanism of chromophore formation.

The mechanism of chromophore biosynthesis in green fluorescent protein (GFP) is triggered by a spontaneous main chain cyclization reaction of residues 65-67. Here, we demonstrate that the initially colorless Y66L variant, designed to trap chromophore precursor states, is oxidatively modified to generate yellow chromophores that absorb at 412 and 374 nm. High- and low-pH crystal structures determined to 2.

The crystal structure of the Y66L variant of green fluorescent protein supports a cyclization-oxidation-dehydration mechanism for chromophore maturation.

The crystal structure of a colorless variant of green fluorescent protein (GFP) containing the Y66L substitution has been determined to 1.5 A. Crystallographic evidence is presented for the formation of a trapped intermediate on the pathway of chromophore maturation, where the peptide backbone of residues 65-67 has condensed to form a five-membered heterocyclic ring.