Rational Design of an Artificial Metalloenzyme by Constructing a Metal-Binding Site Close to the Heme Cofactor in Myoglobin.

In this study, we constructed a metal-binding site close to the heme cofactor in myoglobin (Mb) by covalently attaching a nonnative metal-binding ligand of bipyridine to Cys46 through the F46C mutation in the heme distal site. The X-ray structure of the designed enzyme, termed F46C-mBpy Mb, was solved in the Cu(II)-bound form, which revealed the formation of a heterodinuclear center of Cu-His-H2O-heme. Cu(II)-F46C-mBpy Mb exhibits not only nitrite reductase reactivity but also cascade reaction activity involving both hydrolysis and oxidation. Furthermore, F46C-mBpy Mb displays Mn-peroxidase activity by the oxidation of Mn2+ to Mn3+ using H2O2 as an oxidant. This study shows that the construction of a nonnative metal-binding site close to the heme cofactor is a convenient approach to creating an artificial metalloenzyme with a heterodinuclear center that confers multiple functions.

The ambiguous "internal carotid artery"-Ultrasound diagnosis of congenital absence of the internal carotid artery: A case report and review of the literature.

RATIONALE: Congenital anatomical variation of internal carotid artery (ICA) rarely occurs, and congenital absence of the ICA is even rarer. Few reports are available on the diagnosis of congenital absence of the ICA by carotid doppler ultrasound (CDUS), and most cases have been identified by computed tomographic angiography (CTA) or digital subtraction angiography (DSA). PATIENT CONCERNS: A 61-year-old male was admitted to our hospital due to dizziness for more than half a month. He was hypertensive and had been drinking and smoking for many years. DIAGNOSES: The patient was diagnosed by carotid doppler ultrasound with congenital absence of the right ICA, confirmed by CTA and DSA. A nodular aneurysm in the anterior communicating artery was observed by CTA and DSA. INTERVENTIONS: After relevant preoperative examinations were performed, the patient underwent right craniotomy and clipping of the aneurysm under general anesthesia 8 days after admission. OUTCOMES: The patient recovered well after surgery and no relapses has been observed. LESSONS: Congenital absence of the ICA is rare and usually diagnosed by CTA or DSA in clinical practice. If radiologists do not have adequate knowledge about the associated ultrasonic characteristics, a missed diagnosis may occur. As a noninvasive and rapid screening tool for cervical vascular diseases, carotid doppler ultrasound offers a new approach for the diagnosis of congenital absence of the ICA.

Effects of naturally occurring S47F/A mutations on the structure and function of human cytochrome c.

The sequence and structure of human cytochrome c (hCyt c) exhibit evolutionary conservations, with only a limited number of naturally occurring mutations in humans. Herein, we investigated the effects of the naturally occurring S47F/A mutations on the structure and function of hCyt c in the oxidized form. Although the naturally occurring S47F/A mutations did not largely alter the protein structure, the S47F and S47A variants exhibited a small fraction of high-spin species. Kinetic studies showed that the peroxidase activity of the variants was enhanced by ∼2.5-fold under neutral pH conditions, as well as for the rate in reaction with H2O2, when compared to those of wild-type hCyt c. In addition, we evaluated the interaction between hCyt c and human neuroglobin (hNgb) by isothermal titration calorimetry (ITC) studies, which revealed that the binding constant was reduced by ∼8-fold as result of the mutation of the hydrophilic Ser to the hydrophobic Phe/Ala. These findings provide valuable insights into the role of Ser47 in Ω-loop C in sustaining the structure and function of hCyt c.

Genome-wide analysis of the AINTEGUMENTA-like (AIL) transcription factor gene family in pumpkin (Cucurbita moschata Duch.) and CmoANT1.2 response in graft union healing.

AINTEGUMENTA-like (AIL) proteins are members of the APETALA 2/ETHYLENE RESPONSE FACTOR (AP2/ERF) domain family of transcription factors involved in plant growth, development, and abiotic stress responses. However, the biological functions of AIL members in pumpkin (Cucurbita moschata Duch.) remain unknown. In this study, we identified 12 AIL genes in the pumpkin genome encoding proteins predicted to be localized in the nucleus. Phylogenetic analysis showed that the AIL gene family could be classified into six major subfamilies, with each member encoding two AP2/ERF domains separated by a linker region. CmoAIL genes were expressed at varying levels in the examined tissues, and CmoANT genes showed different expression patterns under auxin (IAA), 1-naphthylphthalamic acid (NPA), and abscisic acid (ABA) treatments. Ectopic overexpression of CmoANT1.2 in Arabidopsis increased organ size and promoted growth of grafted plants by accelerating graft union formation. However, there was no significant difference at the graft junction for WT/WT and WT/ANT under IAA or NPA treatments. Taken together, the results of this study provide critical information about CmoAIL genes and their encoded proteins, and suggest future work should investigate the functions of CmoANT1.2 in the grafting process in pumpkin.

Assessment of regional myocardial function in patients with dilated cardiomyopathy by velocity vector imaging.

OBJECTIVE: To assess the left ventricular (LV) longitudinal systolic and diastolic function in patients with dilated cardiomyopathy (DCM) by syngo Velocity Vector Imaging (VVI). METHODS: Digital dynamic images of 30 DCM patients and 30 healthy subjects were collected; then the longitudinal velocity, strain, and strain rate were measured in systolic early and late diastolic periods, and the time to peak systolic velocity, strain, and strain rate were measured and recorded. The parameters of the two groups were compared. RESULTS: All of the parameters of the DCM were significantly lower than those of the normal group (P < 0.05-0.01), except that the parameter of late diastolic strain was not different between the two groups (P > 0.05). CONCLUSIONS: VVI is a novel noninvasive tool to assess quantitatively and objectively LV regional systolic and diastolic function in patients with DCM; it provides another useful modality for evaluating cardiac function.