Lens membranes VI. Some characteristics of the EDTA-extractable protein (EEP) from bovine lens fiber membranes

One of the protein components of lens fiber membranes is glyceraldehyde 3‐phosphate dehydrogenase

“…About the same polypeptide pattern is obtained with membranes, isolated as the urea-insoluble fraction of lens homogenates [6,7]. Extraction of this preparation by EDTA liberated the Mr 34 000-35 000 [7]. We wish to report here that the Mr 35 000 component from purified lens membranes consists of 3 unrelated polypeptides, one of which is identical with glyceraldehyde 3-phosphate dehydrogenase.…”

“…About the same polypeptide pattern is obtained with membranes, isolated as the urea-insoluble fraction of lens homogenates [6,7]. Extraction of this preparation by EDTA liberated the Mr 34 000-35 000 [7].…”

Sphingolipids in human lens membranes: an update on their composition and possible biological implications

“…These differences may result from the various protocols used for the isolation of HLMs. Most lens-membrane extraction sequences have included treatment with urea or urea/alkaline treatment, followed by a milder detergent (n-octyl-␤-d-glucopyranoside) and a strong chaotropic agent, such as guanidine hydrochloride (Aerts et al, 1990;Alcala et al, 1982;Bloemendal et al, 1972;Bouman et al, 1979Bouman et al, , 1980Bouman et al, , 1981Broekhuyse and Kuhlmann, 1974Broekhuyse et al, 1979;Cotlier et al, 1978;Fleschner and Cenedella, 1991, 1997Horwitz and Bok, 1987;Jarvis and Louis, 1995;Roy et al, 1982;Takemoto and Takehana, 1986;Voorter et al, 1989). Because the solubility of liquid-ordered domains enriched in CHol is temperature-and detergent-dependent (Harder and Simons, 1997;Hooper, 1999), the great variations in the reported molar ratios may reflect different levels of enrichment or depletion of these clusters in the fractions isolated under the various experimental conditions.…”

Calcium-binding lens membrane proteins

“…They can be released from the membranes by means of EDTA or EGTA (Broekhuyse and Kuhlmann, 1978;Bouman et al, 1979;van Raaij et al, 1983a;van Raaij et al, 1983b). These extrinsic membrane proteins, called EEP (EDTA-extractable proteins), are bound to lens fiber membrane structures via calcium (van den Eijnden-van Raaij et al, 1985a).…”