Linked Life Data

14563360

Source:http://linkedlifedata.com/resource/pubmed/id/14563360

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2003-10-17
pubmed:abstractText
Three laminarinases (LAM, LIC 1, and LIC 2) and two cellulases (CEL 1 and CEL 2) were purified to homogeneity from Periplaneta americana midguts. These beta-glucanases are secreted by salivary glands, stabilized by calcium ions, and have pH optima around 6. LAM (46 kDa) is active only on laminarin, native or with oxidized ends, and so it is an endo-beta-1,3-glucanase (EC 3.2.1.39). It processively releases mainly glucose from laminarin and shows lytic activity on fungal cells. LIC 1 (25 kDa) is an endo-beta-1,3(4)-glucanase (EC 3.2.1.6.), because it cleaves internal bonds on both laminarin and lichenin. LIC 1 lyses fungal cells and apparently have high affinity for sequences of cellotetraoses linked by beta-1,3 links, releasing cellotetraose from lichenin. The reaction catalyzed by LIC 1 is not in rapid equilibrium, as suggested by activity-pH data. These data also showed that a group in LIC 1 with pK=4.9 is necessary for substrate binding. LIC 2 (23 kDa) seems to be similar to LIC 1. The laminarinases are inactivated by carbodiimide, suggesting the presence of a carboxyl group involved in catalysis. LAM and LIC 2 are inhibited by excess laminarin as substrate. CEL 1 (72 kDa) and CEL 2 (73 kDa) quickly decrease the molecular weight of lichenin used as substrate. Therefore, they are endo-beta-1,4-glucanases (EC 3.2.1.4). Both CEL 1 and CEL 2 are also active on crystalline cellulose. The specificities of P. americana beta-glucanases agree with the omnivorous detritus-feeding habit of this insect, as they are able to attack plant (CEL 1, CEL 2, LIC 1 and LIC 2) and fungal (LIC 1 and LAM) cell walls.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0965-1748
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1085-97
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:14563360-Animals, pubmed-meshheading:14563360-Carbodiimides, pubmed-meshheading:14563360-Carbohydrate Conformation, pubmed-meshheading:14563360-Catalysis, pubmed-meshheading:14563360-Cellulases, pubmed-meshheading:14563360-Digestive System, pubmed-meshheading:14563360-Enzyme Inhibitors, pubmed-meshheading:14563360-Enzyme Stability, pubmed-meshheading:14563360-Glucans, pubmed-meshheading:14563360-Hydrogen-Ion Concentration, pubmed-meshheading:14563360-Hydrolases, pubmed-meshheading:14563360-Kinetics, pubmed-meshheading:14563360-Molecular Weight, pubmed-meshheading:14563360-Periplaneta, pubmed-meshheading:14563360-Polysaccharides, pubmed-meshheading:14563360-Saccharomyces cerevisiae, pubmed-meshheading:14563360-Salivary Glands, pubmed-meshheading:14563360-Substrate Specificity
pubmed:year
2003
pubmed:articleTitle
Action pattern, specificity, lytic activities, and physiological role of five digestive beta-glucanases isolated from Periplaneta americana.
pubmed:affiliation
Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, 05513-970, São Paulo, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't