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PubMedDate not supplied

Sonographic evaluation of umbilical cord insertion with umbilical coiling index.

PURPOSE: The aim of this study was to investigate the association between umbilical cord hypocoiling and abnormal placental insertion of the umbilical cord. METHODS: Umbilical coiling was measured by sonography in 253 pregnant women in their second or third trimester. An umbilical coiling index, defined here as the reciprocal of the length of 1 umbilical vascular coil, of less than 0.1 was considered hypocoiled. The distance from the placental edge to the insertion of the umbilical cord was measured after delivery, and the results were used to classify cord insertion as normal, marginal, or velamentous. RESULTS: Cord insertion was abnormal in 66.7% of the fetuses with umbilical hypocoiling but in only 1.3% of those whose coiling index was > or = 0.1 (p < 0.05). CONCLUSIONS: Hypocoiling of the umbilical cord was highly associated with abnormal cord insertion. The presence of a hypocoiled umbilical cord may indicate the presence of abnormal cord insertion and thus may be useful for obstetric management.

Adult↗
PubMed1999

Insertion of the abductor hallucis muscle in feet with and without hallux valgus.

Textbooks of human anatomy present different opinions on the insertion of the abductor hallucis muscle which is concerned in etiology as well as in therapy of hallux valgus. In plastic and reconstructive surgery the muscle is taken as a graft for flap-surgery. In this study 109 feet (58 right, 51 left) were examined, 18 of these with clinical hallux valgus. The tendon of the muscle may attach to the tendon of the medial head of the short flexor hallucis muscle where a subtendineous bursa can be found. At the head of the first metatarsal bone the joint capsule is reinforced by fibres arising from the medial sesamoid bone which may be called "medial sesamoidal ligament." The tendon passes the first metatarsophalangeal joint plantarily to its transverse axis. Three types of insertion could be distinguished: type A, insertion at the proximal phalanx (N = 42); type B, insertion at the medial sesamoid ligament and at the medial sesamoid bone (N = 65); type C, insertion at the medial sesamoid bone (N = 2). In all types superficial fibres of the tendon extended to the medial and plantar sides of the base of the proximal phalanx, running in a plantar to dorsal direction. Statistical analysis exposed neither significant differences between both sides nor significant difference between normal feet and feet with hallux valgus. Therefore, a specific pattern of insertion of the abductor hallucis muscle in hallux valgus cannot be stated.

Foot↗
PubMed2002

Insertion of unsaturated organic electrophiles into molybdenumbond-alkoxide and rheniumbond-alkoxide bonds of neutral, stable carbonyl complexes.

Alkoxo complexes [Re(OR)(CO)(3)(N-N)] (R=Me, Et, tBu; N-N=2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'bipyridine (bipy'), 1,10-phenanthroline (phen)) and [M(OMe)(eta(3)-allyl)(CO)(2)(phen)] (M=Mo, W) have been synthesized in good yields and using mild conditions by the reaction of sodium alkoxides with [Re(OTf)(CO)(3)(N-N)] and [MCl(eta(3)-allyl)(CO)(2)(phen)] precursors. These have been characterized by IR and NMR spectroscopy as well as by X-ray diffraction for [W(OMe)(eta(3)-allyl)(CO)(2)(phen)] (10). The reactions of the molybdenum and rhenium alkoxo complexes with isocyanates, R'NCO, yield [L(n)M[N(R')C(O)OR]] complexes; the carbamate ligand, which results from an R'NCO insertion into the Mbond;OR bond, is monodentate through the nitrogen atom. The solid-state structures of Mo and Re examples have been determined by X-ray diffraction. The geometry around the carbamate nitrogen of these compounds is planar, and the distances indicate delocalization of the nitrogen lone pair involving mainly the carbonyl groups. Experiments carried out with the Re complexes showed that aryl isocyanates are more reactive than their alkyl counterparts, and that bulky R' groups led to slow rates of insertion. Insertion reactions were also observed with isothiocyanates, although here it is the Sbond;C bond that inserts into the Mbond;OR bond, and the resulting ligand is bound to the metal by sulfur. Competition experiments with the Re compounds indicate that isocyanates are more reactive than isothiocyanates towards the Rebond;OR bonds. Tetracyanoethylene inserts into the Rebond;OMe bond of [Re(OMe)(CO)(3)(bipy')], forming a complex with a 2-methoxytetracyanoethyl ligand; the structure of which was determined by X-ray diffraction. The formation of the xanthato complex [Re(SC(S)OtBu)(CO)(3)(bipy)] (20) by reaction of [Re(OTf)(CO)(3)(bipy)] with CS(2) and NaOtBu, but not by the reaction of CS(2) and [Re(OtBu)(CO)(3)(bipy)] (5 a), suggests that the insertion reactions do not take place by ionization of the alkoxo complexes to give the free alkoxide ion.

Journal Article↗
PubMed2006

Descriptive anatomy of the insertion of the biceps femoris muscle.

The biceps femoris is the most lateral component of the so-called hamstring muscles. Classically, this muscle's insertion into the head of the fibula has been described but further details of its anatomy have not been universally appreciated. Additional insertions into the crural fascia and tibia have been described. We dissected 56 cadavers paying especially close attention to the insertion of the biceps femoris muscle. The tendon of this muscle was found to have both medial and lateral slips each with an anterior and posterior component. Further, we found an attachment not only into the lateral condyle of the femur but also the popliteus tendon and arcuate popliteal ligament. Our study has found that the tendon of insertion of the biceps femoris muscle is more complex than described previously and suggests that this tendon may be far more important in knee stability based on the multiple attachment sites found. We hypothesize that there may be a synergistic effect between the biceps femoris and the popliteus muscles based on our findings of an additional attachment of the biceps femoris tendon into the popliteus tendon. This study provides new detailed nomenclature for the description of the tendon of insertion of the biceps femoris muscle and indicates that the current description of the insertion of the tendon of the biceps femoris muscle should be revised. The clinician must have a thorough understanding of this anatomy before correct therapeutic maneuvers can be implemented.

Humans↗
PubMed1989

The unique insert of cellular and viral fms protein tyrosine kinase domains is dispensable for enzymatic and transforming activities.

The receptors for colony stimulating factor-1 (CSF-1), platelet derived growth factor and the c-kit protein tyrosine kinase (PTK) contain within their catalytic domains a stretch of 60-100 residues, largely unrelated in sequence, with no counterpart in other PTKs. Of the 64 amino acids within this kinase insert, 58 were deleted from the mouse CSF-1 receptor by oligonucleotide-directed mutagenesis. The mutant CSF-1 receptor was not markedly affected in its kinase activity, post-translational processing or its ability to induce autocrine transformation of NIH 3T3 mouse fibroblasts. Similarly, retention of kinase and transforming activities were observed following deletion of part or all of the kinase insert from the v-fms oncoprotein. The c- and v-fms kinase inserts were probed using monoclonal and polyclonal antibodies and were found to be highly antigenic. Two monoclonal antibodies raised to the v-fms cytoplasmic domain both recognized epitopes within the insert, and bound enzymatically active v-fms glycoproteins. These results indicate that the fms kinase insert is located on the surface of the protein and folds separately from the rest of the catalytic domain, but is not required for the biological activity of fms PTKs ectopically expressed in mouse fibroblasts. The insert may therefore play a specific function in cells such as monocytes and trophoblasts that normally express the CSF-1 receptor.

Amino Acid Sequence↗
PubMed1991

The role of kinase activity and the kinase insert region in ligand-induced internalization and degradation of the c-fms protein.

Molecular steps in endocytosis and degradation of the c-fms protein were analyzed by following the fate of mutated c-fms molecules after M-CSF binding. A mutant c-fms protein lacking tyrosine kinase activity was rapidly internalized after M-CSF binding but not degraded. Another mutant c-fms molecule that lacked most of the kinase insert region was similarly internalized after M-CSF binding and also not degraded. This indicates that the signal for internalization is separate from that directing degradation of the receptor. It has been shown previously that a c-fms mutant in which the kinase insert domain is deleted retains tyrosine kinase activity but lacks two major sites of autophosphorylation. The degradation step therefore requires both kinase activity and the kinase insert region whereas the internalization step is independent of these factors. The major sites of tyrosine autophosphorylation within the kinase insert region were next mutated to determine whether autophosphorylation in the kinase insert region of c-fms might be the signal that triggers degradation of internalized receptors. These mutant receptors were still rapidly degraded in response to M-CSF. Therefore, ligand-induced degradation of c-fms may require tyrosine phosphorylation of a protein other than the c-fms receptor itself and the kinase insert region may be necessary for recognition of this substrate.

Animals↗
PubMed1997

Significance of granulation tissue in torn supraspinatus insertions: an immunohistochemical study with antibodies against interleukin-1 beta, cathepsin D, and matrix metalloprotease-1.

The pathophysiology of rotator cuff tears can be elucidated by examining the tendinous insertion of the supraspinatus muscle. As seen by light microscopy, the granulation tissue around the insertion of a torn supraspinatus tendon appears to induce osteochondral destruction by means of multinucleated giant cells and chemical mediators. The purpose of this study was to examine the contribution of certain chemical mediators to osteochondral destruction using immunohistochemical analysis of interleukin-beta, cathepsin D, and matrix metalloprotease-1. Sixteen supraspinatus insertions with portions of the greater tuberosity, including eight complete-thickness tears and eight incomplete-thickness tears, were obtained during surgery. Six fresh cadaveric supraspinatus tendons without grossly evident tears served as normal controls. Strong immunoreactivity was found in all 16 torn supraspinatus insertions but not in the six insertions of apparently intact tendons. Macrophages and multinucleated giant cells, which showed immunoreactivity for all three chemical mediators, were often found at the interface between the osteochondral margin of the enthesis and the granulation tissue, suggesting that they may be involved in osteochondral destruction. We therefore concluded that, in addition to repetitive subacromial impingement, this granulation tissue may contribute to the development of rotator cuff tears by weakening the insertion.

Adult↗
PubMed1998

Deformation of femoral nails with intramedullary insertion.

Current methods of distal interlocking of intramedullary femoral nails are dependent on image intensification. However, radiation exposure to the patient, the operating room staff, and the surgeon remains a concern. Proximally mounted, radiation-free aiming systems for distal interlocking of femoral nails have reportedly failed because of nail deformation with insertion. To better understand this deformation, a three-dimensional magnetic motion tracking system was used to determine the position of the distal interlocking hole following nail insertion. The amount and direction of deformation of commercially available small-diameter implants (unslotted 9-mm nails inserted without reaming) and large-diameter implants (slotted 13-mm nails inserted with reaming) from a single manufacturer were analyzed. Measurements of deformation (three translations and three angles), based on the center of the distal transverse locking hole, were performed on 10 paired intact human cadaveric femora before and after insertion. The technique produced the following results for the small and large-diameter nails, respectively: lateral translations of 18.1+/-10.0 mm (mean+/-SD, range: 47.8 mm) and 21.5+/-7.9 mm (range: 26.4 mm), dorsal translations of -3.1+/-4.3 mm (range: 15.2 mm) and 0.4+/-9.8 mm (range: 30.1 mm), and rotation about the longitudinal axes of -0.1+/-0.2 degrees (range: 0.7 degrees) and 10.0+/-3.1 degrees (range: 7.8 degrees). This technique is useful for measuring insertion-related femoral nail deformation. The data for the nails tested suggest that a simple aiming arm, mounted on the proximal end of the femoral nail alone, will not sufficiently provide accurate distal aiming.

Bone Nails↗
PubMed2004

Effectiveness of fixed 50% nitrous oxide oxygen mixture and EMLA cream for insertion of central venous catheters in children.

BACKGROUND: Although the equimolecular mixture of oxygen and nitrous oxide (EMONO) seems a good choice to relieve procedure-related pain in children, it has not been evaluated for insertion of central venous catheters in children. To assess the safety and the effectiveness of this gas mixture for insertion of central venous catheters, we conducted a prospective observational study. PROCEDURE: This study was performed by the "Centre National de Greffe de Moelle Osseuse." Procedure and inhalation characteristics, as well as pain evaluations and side effects, were reported. RESULTS: Fifty central venous catheters were inserted in 50 consecutive children. Median age was 7 (range, 4-13) years. An anesthesiologist was responsible for delivering EMONO, and provided constant surveillance throughout the procedure. EMLA cream was applied 2 hr before EMONO inhalation. No associated drugs were used. All catheters were inserted by the same experienced physician in the operating theater. Median inhalation length was 5 min (range, 3-6) before starting catheter's insertion and 12 min (range, 9-25) for the total inhalation. Median procedural pain evaluations were 10 (range, 0-30) for children on a 0-100 visual analog scale (VAS). Minor side effects were observed during eight (16%) inhalations. These side effects were euphoria (14%), deep sedation (4%), nausea and vomiting (2%), hallucinations (2%). All side effects were transient and resolved within 5 min after removing the inhalation device. CONCLUSIONS: This study which shows that EMONO is effective for insertion of central venous catheters in children and represents a simple and safe alternative to general anesthesia.

Adolescent↗
PubMed1990

Accommodation of single amino acid insertions by the native state of staphylococcal nuclease.

Single alanine and glycine insertions were introduced at 20 randomly selected positions in staphylococcal nuclease. The resulting changes in catalytic activity and in stability to guanidine hydrochloride denaturation indicate that the native state structure is frequently able to accommodate the extra residue without great difficulty, even insertions within secondary structural elements such as alpha helices and beta sheets. On average, an inserted residue reduces the free energy of denaturation (delta GH2O) by an amount roughly comparable to an alanine or glycine substitution for one of the residues flanking the site of insertion. Several positions outside of the enzyme active site were found where insertions, but not substitutions, lead to structural changes that modify catalytic activity and the circular dichroism spectrum. Amino acid insertions represent a virtually unexplored class of genetic mutation that may prove complementary to amino acid substitutions for engineering proteins with altered functional and structural properties.

Alanine↗
PubMed2002

Probing reactive center loop insertion in serpins: a simple method for ovalbumin.

Insertion of the reactive center loop in beta-sheet A in serpins has been typically inferred from the increased stability of the cleaved form to thermal- and urea-induced denaturation. We describe a convenient and rapid fluorescence-based method that differentiates the loop-inserted form from the loop-exposed form in ovalbumin, a prototypic noninhibitory serpin. Recombinant wild-type and R345A ovalbumins in the intact form bind ANS with equilibrium dissociation constants of 116 and 125 microM and a maximal fluorescence increase of 200 and 264%, respectively, in pH 6.8 buffer. Cleavage of the two proteins with porcine pancreatic elastase results in a 1.6- and 2.6-fold increase in the ANS-binding affinity. While cleavage of the reactive center loop in rR345A ovalbumin results in a approximately 200% increase in the ANS fluorescence, the rWT protein exhibits a approximately 50% decrease. Similar experiments with alpha(1)-proteinase inhibitor and antithrombin, two inhibitory serpins that exhibit reactive center loop insertion, show a decrease in ANS fluorescence on cleavage with porcine pancreatic elastase and thrombin, respectively. Denaturation studies in guanidinium hydrochloride indicate that the reactive center loop is inserted in the main body of the serpin in the cleaved form of rR345A mutant, while it is exposed in the cleaved form of rWT ovalbumin. These results demonstrate that ANS fluorescence change is an indicator of the loop-inserted or loop-exposed form in these recombinant ovalbumins, and thus could be advantageously used for probing reactive center loop insertion in ovalbumins. The major increase in fluorescence for the rR345A mutant on cleavage primarily arises from a change in ANS binding rather than from the generation of an additional ANS-binding site.

Amino Acid Substitution↗
PubMed1998

Electrostatic and Hydrophobic Effects of Oligopeptide Insertions on Protein Adsorption.

The effects of oligopeptide insertions on the adsorption of the protein ZZ, where Z is the IgG binding domain of staphylococcal Protein A, was investigated by in situ ellipsometry. In particular, the interplay between hydrophobic and electrostatic interactions as driving force for adsorption was investigated by studying the effects of oligopeptide insertions of the type Tn((AlaTrpTrpPro)n), Nn((AlaTrpTrpAspPro)n), and Pn((AlaTrpTrpLysPro)n) on the adsorption at silica, methylated silica, and diaminocyclohexane (DACH) plasma polymer surfaces. For comparison, the adsorption of the inserted peptide stretches was also investigated. It was found that the adsorption of all the peptides increases with the molecular weight at methylated silica. At silica, only the Pn peptides were found to adsorb. The net negatively charged proteins modified through peptide insertions did not adsorb at the hydrophilic and negatively charged silica, irrespective of the peptide insertion, whereas an extensive adsorption was found for the positively charged DACH surface for all the proteins investigated. For hydrophobic and negatively charged methylated silica, on the other hand, the peptide insertions were found to have a major influence on the protein interfacial behavior, and the adsorption followed the peptide stretch charge, thus increasing in the order ZZNn < ZZTn < ZZPn. These effects are discussed in terms of the relative importance of hydrophobic and electrostatic interactions as driving force for the adsorption. Copyright 1998 Academic Press.

Journal Article↗
PubMed1993

Analysis of the chloroplast large subunit ribosomal RNA gene from 17 Chlamydomonas taxa. Three internal transcribed spacers and 12 group I intron insertion sites.

Previous reports on the chloroplast large subunit rRNA genes of the two distantly related green algae Chlamydomonas eugametos and Chlamydomonas reinhardtii indicate differences in the distribution of group I introns and suggest a different arrangement of internal transcribed spacers. To provide insights into the origin of these two types of intervening sequences, we have undertaken the sequencing of the chloroplast rrnL genes of 15 additional Chlamydomonas taxa and have characterized the mature large subunit rRNA species they encode in addition to those specified by the C. reinhardtii rrnL. These analyses disclosed the presence of three internal transcribed spacers sharing the same positions in all of the 17 taxa as well as the presence of a total of 39 group I introns representing 12 insertion sites. Of these insertion sites, only one has been identified in non-Chlamydomonas taxa. The distribution of Chlamydomonas introns is highly variable and, in many respects, is not consistent with the phylogeny deduced from chloroplast rRNA sequence comparisons. This phylogeny features two main lineages of Chlamydomonas taxa forming sister groups. Because earlier branching organisms in the green algal/land plant lineage display no chloroplast rDNA introns, it appears that all of the intron insertion positions in Chlamydomonas are of recent origins, with some of the positions having arisen subsequent to the divergence of the two main Chlamydomonas lineages. Remarkably, the rRNA regions corresponding to most of the group I intron insertion positions in rRNA genes have been assigned functional roles suggesting that they lie in exposed regions of the ribosome. On the basis of this striking correlation between exposed rRNA regions and intron insertion sites, we speculate that the reversal of the self-splicing reaction has played a major role in the creation of the multiple intron insertion positions found in rRNA genes as well as in the proliferation of group I introns elsewhere in the Chlamydomonas chloroplast genome.

Animals↗
PubMed1993

In planta deletion of DNA inserts from the large intergenic region of cauliflower mosaic virus DNA.

RNA splicing and copy-choice recombination lead to deletions in the DNA of cauliflower mosaic virus (CaMV). To assess the relative importance of these mechanisms of nucleotide sequence change, free of constraints imposed by the "relay race" mode of translation of CaMV RNA, we examined the stability of inserts in the large intergenic region. The insertions had, in various combinations, splicing signals and directly repeated sequences that could facilitate deletion. Most modified DNAs were infectious. Viral DNA recovered from infected plants was analyzed by restriction and, in some cases, cloned for nucleotide sequencing to determine deletion endpoints. Deletions from a DNA containing introduced splicing signals occurred primarily at direct repeats, although deletion apparently by splicing was also detected. Both types of deletion were also observed with insertions containing a 5' splice donor but no known functional 3' splice acceptor. One DNA, whose insertion lacked splicing signals and short repeated sequences, was stable in one of two plants infected. Total insert deletions were bounded by repeats or pseudorepeats, while partial insert deletions apparently occurred by splicing. The results suggest that the two mechanisms for deletion of nucleotides are equally important in the evolution of caulimoviral nucleotide sequences.

Base Sequence↗
PubMed1993

RNA insertions and gene duplications in the nonstructural protein p125 region of pestivirus strains and isolates in vitro and in vivo.

Sixteen cytopathogenic (cp) bovine viral diarrhea virus (BVDV) strains/isolates were screened for the existence of RNA insertions in the p125 gene region and/or for p80 gene duplications using the polymerase chain reaction after reverse transcription. Three strains/isolates were shown to contain insertions, and in three others gene duplications were demonstrated. One strain was shown to contain a gene duplication in addition to an insertion. Insertions or duplications were absent in the genomes of 10 non-cp BVD virus strains/isolates, in 4 hog cholera (HC) virus strains, and in 9 of the 16 cp BVD virus strains/isolates analyzed. These results indicate that RNA insertions and gene duplications, although significant, are not the only mechanism contributing to cytopathogenicity in vitro. The RT-PCR was also applied to RNA isolated from tissues of a calf suffering from mucosal disease. Insertion-containing amplification products could be demonstrated in an organ-specific pattern.

Animals↗
PubMed1990

The apoprotein precursor of the major light-harvesting complex of photosystem II (LHCIIb) is inserted primarily into stromal lamellae and subsequently migrates to the grana.

The formation of the lateral distribution of the major antenna complex of photosystem II (LHCIIb) between the granal and stromal lamellae was studied. Specifically, the localization of the insertion and the assembly of the precursor of the apoprotein of LHCIIb (pLHCP) were studied with isolated thylakoids. After insertion of pLHCP into isolated thylakoids, fractionation of the latter into granal and stromal lamellar was performed. At 25 degrees C most of the precursor was located in the granal lamellae, although both highly purified granal and stromal lamellar fractions demonstrated a similar capability to insert pLHCP. When the insertion reaction to the thylakoids was performed at 10 degrees C, followed by their separation into stromal and granal lamellae, the labelled pLHCP was localized in the stromal ones. To examine whether pLHCP inserts into both granal and stromal lamellae, or preferentially into stromal lamellae and subsequently migrating to granal lamellae, a chase experiment was performed. Insertion of pLHCP at 10 degrees C was followed by chase of the radioactive precursor with excess of non-radioactive pLHCP at 25 degrees C. From the results presented it is evident that the level of pLHCP in stromal lamellae was gradually reduced, while it gradually accumulated in the granal lamellae. Furthermore, the pLHCP in the stromal lamellae was found to be in a 'free' form, while after migrating to the granal lamellae it assembled into the pigmented LHCIIb.

Apoproteins↗
PubMed1992

Evolutionary origin of a Kunitz-type trypsin inhibitor domain inserted in the amyloid beta precursor protein of Alzheimer's disease.

The Kunitz-type protease inhibitor is one of the serine protease inhibitors. It is found in blood, saliva, and all tissues in mammals. Recently, a Kunitz-type sequence was found in the protein sequence of the amyloid beta precursor protein (beta APP). It is known that beta APP accumulates in the neuritic plaques and cerebrovascular deposits of patients with Alzheimer's disease. Collagen type VI in chicken also has an insertion of a Kunitz-type sequence. To elucidate the evolutionary origin of these insertion sequences, we constructed a phylogenetic tree by use of all the available sequences of Kunitz-type inhibitors. The tree shows that the ancestral gene of the Kunitz-type inhibitor appeared about 500 million years ago. Thereafter, this gene duplicated itself many times, and some of the duplicates were inserted into other protein-coding genes. During this process, the Kunitz-type sequence in the present beta APP gene diverged from its ancestral gene about 270 million years ago and was inserted into the gene soon after duplication. Although the function of the insertion sequences is unknown, our molecular evolutionary analysis shows that these insertion sequences in beta APP have an evolutionarily close relationship with the inter-alpha-trypsin inhibitor or trypstatin, which inhibits the activity of tryptase, a novel membrane-bound serine protease in human T4+ lymphocytes.

Alzheimer Disease↗
PubMed1995

Oriented channel insertion reveals the motion of a transmembrane beta strand during voltage gating of VDAC.

Yeast VDAC channels (isolated from the mitochondrial outer membrane) form large aqueous pores whose walls are believed to consist of 1 alpha helix and 12 beta strands. Each channel has two voltage-gating processes: one closes the channels at positive potentials, the other at negative. When VDAC is reconstituted into phospholipid (soybean) membranes, the two gating processes have virtually the same steepness of voltage dependence and the same midpoint voltage. Substituting lysine for glutamate at either end of one putative beta strand (E145K or E152K) made the channels behave asymmetrically, increasing the voltage dependence of one gating process but not the other. The asymmetry was the same whether 1 or 100 channels were in the membrane, indicating oriented channel insertion. However, the direction of insertion varied from membrane to membrane, indicating that the insertion of the first channel was random and subsequent insertions were directed by the previously inserted channel(s). This raises the prospect of an auto-directed insertion with possible implications to protein targeting in cells. Each of the mutations affected a different gating process because the double mutant increased voltage dependence of both processes. Thus this strand may slide through the membrane in one direction or the other depending on the gating process. We propose that the model of folding for VDAC be altered to move this strand into the sensor region of the protein where it may act as a tether and guide/restrict the motion of the sensor.

Amino Acid Sequence↗