Carbonic anhydrase generates a pH gradient in Bombyx mori silk glands

Show simple item record Domigan, Laura en Andersson, M en Alberti, KA en Chesler, M en Xu, Q en Johansson, J en Rising, A en Kaplan, DL en 2017-08-14T21:33:46Z en 2015-09-03 en 2015-10 en
dc.identifier.citation Insect Biochemistry and Molecular Biology, 65:100-106 Oct 2015 en
dc.identifier.issn 0965-1748 en
dc.identifier.uri en
dc.description.abstract Silk is a protein of interest to both biological and industrial sciences. The silkworm, Bombyx mori, forms this protein into strong threads starting from soluble silk proteins using a number of biochemical and physical cues to allow the transition from liquid to fibrous silk. A pH gradient has been measured along the gland, but the methodology employed was not able to precisely determine the pH at specific regions of interest in the silk gland. Furthermore, the physiological mechanisms responsible for the generation of this pH gradient are unknown. In this study, concentric ion selective microelectrodes were used to determine the luminal pH of B. mori silk glands. A gradient from pH 8.2 to 7.2 was measured in the posterior silk gland, with a pH 7 throughout the middle silk gland, and a gradient from pH 6.8 to 6.2 in the beginning of the anterior silk gland where silk processing into fibers occurs. The small diameter of the most anterior region of the anterior silk gland prevented microelectrode access in this region. Using a histochemical method, the presence of active carbonic anhydrase was identified in the funnel and anterior silk gland of fifth instar larvae. The observed pH gradient collapsed upon addition of the carbonic anhydrase inhibitor methazolamide, confirming an essential role for this enzyme in pH regulation in the B. mori silk gland. Plastic embedding of whole silk glands allowed clear visualization of the morphology, including the identification of four distinct epithelial cell types in the gland and allowed correlations between silk gland morphology and silk stages of assembly related to the pH gradient. B. mori silk glands have four different epithelial cell types, one of which produces carbonic anhydrase. Carbonic anhydrase is necessary for the mechanism that generates an intraluminal pH gradient, which likely regulates the assembly of silk proteins and then the formation of fibers from soluble silk proteins. These new insights into native silk formation may lead to a more efficient production of artificial or regenerated silkworm silk fibers. en
dc.description.uri en
dc.format.medium Print-Electronic en
dc.language English en
dc.publisher Elsevier en
dc.relation.ispartofseries Insect Biochemistry and Molecular Biology en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from en
dc.rights.uri en
dc.subject Exocrine Glands en
dc.subject Animals en
dc.subject Bombyx en
dc.subject Methazolamide en
dc.subject Silk en
dc.subject Carbonic Anhydrases en
dc.subject Carbonic Anhydrase Inhibitors en
dc.subject Proton-Motive Force en
dc.subject Larva en
dc.subject Hydrogen-Ion Concentration en
dc.title Carbonic anhydrase generates a pH gradient in Bombyx mori silk glands en
dc.type Journal Article en
dc.identifier.doi 10.1016/j.ibmb.2015.09.001 en
pubs.begin-page 100 en
pubs.volume 65 en
dc.rights.holder Copyright: Elsevier en
dc.identifier.pmid 26365738 en en
pubs.end-page 106 en
pubs.publication-status Published en
dc.rights.accessrights en
pubs.subtype Article en
pubs.elements-id 501688 en Engineering en Chemical and Materials Eng en
dc.identifier.eissn 1879-0240 en
pubs.record-created-at-source-date 2017-08-15 en 2015-09-11 en
pubs.dimensions-id 26365738 en

Files in this item

Find Full text

This item appears in the following Collection(s)

Show simple item record


Search ResearchSpace