Prolidase in the Marine Sponge Suberites domuncula: Enzyme Activity, Molecular Cloning, and Phylogenetic Relationship

Abstract

: The enzyme prolidase hydrolyzes the peptide bond that involves the imino nitrogen of proline or hydroxyproline; hence, it catalyzes the final step in collagen degradation. From mammals it is known that this enzyme plays a major role in the recycling of proline for collagen synthesis and can be considered to be essential for the control of cell growth. The dominant organic exoskeleton in sponges, especially in Demospongiae, is collagen and the collagen-related spongin. Here we demonstrate that crude extracts of the demosponge Suberites domuncula contain prolidase or prolidase-like activity. The complementary DNA encoding the putative prolidase was cloned from a library of the same animal. Two different forms of cDNAs, termed SDPEPD1 and SDPEPD2, were identified, coding for the putative polypeptides PEPD_SD-1 with a molecular mass of 55,805 Da and PEPD_SD-2 with 51,684. Evidence is presented suggesting that the two different transcripts originate from the same gene but are formed by an alternative splicing event. We conclude that demosponges contain the activity as well as the gene for prolidase, a major enzyme involved in collagen metabolism, spicule formation, and cell motility. Phylogenetic analysis revealed that the sponge prolidase branches off first from the common ancestor of metazoan prolidases and later than the yeast prolidase; only distantly related are the bacterial enzymes.

Biochemical and biophysical characterization of collagens of marine sponge, Ircinia fusca (Porifera: Demospongiae: Irciniidae)

“…It is well known that collagen is the only intercellular organic framework and amounts to approximately 10% of the total organic matter in Demospongiae [27], which was experimentally proven for the collagen content of I. fusca (≈7%) in the present study. It is also evidenced previously that not all the organic components were resolved for sponge biochemical content which can be correlated to the growth rate potential [28].…”

Collagen from the Marine Sponges Axinella cannabina and Suberites carnosus: Isolation and Morphological, Biochemical, and Biophysical Characterization

“…It has also been proven that in Demospongiae, collagen, constituting exclusively the intercellular organic framework, amounts to approximately 10% of the total organic matter [27,67]. In the present study, collagen content was experimentally calculated to amount for the 12.6% and 5.0% dry weight of A. cannabina and S. carnosus , respectively.…”

Identification and Expression of the SOS Response, aidB-Like, Gene in the Marine Sponge Geodia cydonium: Implication for the Phylogenetic Relationships of Metazoan Acyl-CoA Dehydrogenases and Acyl-CoA Oxidases

“…The translation initiation site, TTGC-CATGA (the putative start codon is in boldface), is of medium strength (Kozak 1991). The truncated signal polyadenylation site AATAA (Zarkower et al 1986) is present (nt 2003 to nt 2007 ) as in most cDNAs from G. cydonium (Wiens et al 1998).…”